Grammar Hyphens with Numbers |
The Blue Book of Grammar and Punctuation

Hyphens with Numbers

Should you write 13-feet or 13 feet? Here is the rule: when you’re combining two or more words to form a compound adjective in front of a noun, put hyphens between these words.

Examples:
Lara handed me a 15-foot pole.
An eighteen-inch monitor is too big for my desk.
Emergency room nurses work 12-hour shifts.
Anthony swung his five-pound hammer.

In the above sentences, the measurements are compound adjectives describing nouns.

When numbers are not used as compound adjectives preceding nouns, don’t use a hyphen. (But remember, all two-word numbers from twenty-one to ninety-nine must be hyphenated in all cases.)

Examples:
Suzanne won the race by a solid 15 feet.
The room was 17 feet long.
Twelve hours later, he was exhausted.
Anthony’s hammer weighs five pounds.

To learn more about hyphens, click here.

Pop Quiz

Correct or incorrect?

1. Stella had her hair cut six-inches last week.

2. Her party shoes had three inch heels.

3. Can you lend me your five-foot tape measure?

4. I am 5-feet-2-inches in my bare feet.

5. The water level rose 10-inches in just three hours.

Pop Quiz Answers

1. Stella had her hair cut six inches last week.

2. Her party shoes had three-inch heels.

3. Can you lend me your five-foot tape measure? (Correct)

4. I am 5 feet 2 inches in my bare feet.

5. The water level rose 10 inches in just three hours.

If the article or the existing discussions do not address a thought or question you have on the subject, please use the "Comment" box at the bottom of this page.

310 responses to “Hyphens with Numbers”

  1. Cathy S says:

    What is the proper way to write the numbers and compound adjectives in the following sentence?
    The site consists of a 5,010 square foot parcel that is occupied by a 15,030 square foot commerical building that was built in 1920.
    Thank you.

    • Our blog post on “Numbers as Adjectives” addresses this issue. The rule says, “Generally, hyphenate between two or more adjectives when they come before a noun and act as a single idea. This rule can also be applied when a number and a measurement unit taken together form an adjective, that is, when they describe another object.”
      Examples:
      A 22-inch monitor is too big for my desk.
      Nurses work 12-hour shifts.

      Therefore, the proper way to write the sentence would be:

      The site consists of a 5,010-square-foot parcel that is occupied by a 15,030-square-foot commerical building that was built in 1920.

      • Dinora de Rivera says:

        What about writing 12-mm focal length? Hyphen or no hyphen?

        • According to The Chicago Manual of Style, hyphens are never used between the numeral and the abbreviation or symbol, even when they are in adjectival form. Therefore write 12 mm focal length.

  2. Ashley says:

    Where does the hyphen go?
    The date of manufacture of the first floor 2 1/2-ton condensing unit is 2000.
    The date of manufacture of the first floor 2-1/2 ton condensing unit is 2000.

    • Your example sentence contains two compound adjectives, first-floor and 2 1/2-ton. The hyphens come between the adjectives. Our rule 4 in Hyphens states, “Generally, hyphenate between two or more adjectives when they come before a noun and act as a single idea.” This rule can also be applied when a number and a measurement unit taken together form an adjective, that is, when they describe another object.

      The date of manufacture of the first-floor, 2 1/2-ton condensing unit is 2000. OR
      The first-floor, 2 1/2-ton condensing unit was manufactured in the year 2000.

      • Ben Zismann says:

        This example is similar to what I’m looking to write and I’m a little confused about the description. It could be read as either “two half ton” or “two and a half ton.” If the latter is true, shouldn’t it be “2-1/2-ton,” with a hyphen between both the fraction and the unit?

        • If you look at the noun following the compound adjective, you will see it is the singular noun unit. If it were “two half-ton,” the noun following would be the plural noun units. There is no hyphen used between the number two and the fraction when writing the number 2 1/2.

  3. Maria says:

    I am updating the bylaws and I have a question about punctuation. Here is my paragraph:

    All members are required to fulfill two 3-hour maintenance day commitments. A three-hour maintenance day is defined as one person working for a total of three (3) hours or two persons working for 90 minutes. Exclusions are Parent/Tot families and Board members; both are required to fulfill one 3-hour maintenance day.

    What is the correct punctuation? Where do I add actual numbers in parentheses and how do I punctuate sentences where two numbers are back-to-back, such as “two 3-hour maintenance days”?

    • Since your document is not densely populated with large numbers, you do not need to include the numerals in parentheses. By being consistent in the use of numerals for numbers describing time and writing out the other small numbers, you can avoid having to insert punctuation, such as commas. Also, since you are defining a term, we recommend using italics for the term itself and enclosing the definition in quotes. Therefore, your paragraph would look like this:

      All members are required to fulfill two 3-hour maintenance day commitments. A 3-hour maintenance day is defined as “one person working for a total of 3 hours or two persons working for 90 minutes.” Exclusions are parent/tot families and board members; both are required to fulfill one 3-hour maintenance day.

  4. Asok says:

    I am thankful to your excellent Website, GrammarBook.com, which has benefited me a lot. May I request you to please explain why it is written “3-year Degree Course instead of 3 years Degree Course.”
    Thanks.

    • The phrase “three-year-degree” is a compound adjective that acts as a single idea and describes the singular noun course. A compound adjective in front of a noun requires hyphens. Also, spell out single-digit whole numbers. Since you are not referring to a specific course title, it does not need to be capitalized. Thus, “three-year-degree course.”

      If not used as an adjective, you might write this: It takes three years to complete the course work and obtain the degree.

      • Hugh says:

        I’m late to this party; fashionably late? You decide.

        I would suggest that Asok’s degree course takes three years, hence it would be a “three-year degree course”; it is a degree course, rather than an x-degree course.

        I came here seeking confirmation of my own inclination for hyphenation on the phrase “five 20 kg bags”, which I am now confident in writing as “five 20-kg bags”. Please let me know if that is not correct.

        • Asok’s sentence is open to interpretation. Our interpretation was that the compound adjective three-year-degree describes the noun course. Your interpretation is that the compound adjective three-year describes degree course. There is no right or wrong answer, as the meaning of the sentence is unclear and should probably be rewritten.

          In regard to your second question, in accordance with the Chicago Manual of Style’s Rule 9.16, hyphens are never used between the numeral and an abbreviation or symbol, even when they are in adjectival form. Therefore, write “five 20 kg bags.”

          • Hugh says:

            Thanks for this response.

            Regarding the five 20 kg bags, I take your point about not hyphenating numerals and units. How about “20 five-kg bags” or “20 five-kilogram bags”?

  5. Kristen says:

    Which of the following is correct:

    The smallest book in the Library of Congress measures one-twenty-fifth inch by one-twenty-fifth inch.

    or

    The smallest book in the Library of Congress measures one-twenty fifth inch by one-twenty fifth inch.

    or

    The smallest book in the Library of Congress measures one twenty-fifth inch by one twenty-fifth inch.

    Thanks

    • The Chicago Manual of Style‘s hyphenation guide says, “Simple fractions are hyphenated in noun, adjective, and adverb forms except when the second element is already hyphenated.”

      The smallest book in the Library of Congress measures one twenty-fifth inch by one twenty-fifth inch.

  6. mitzi says:

    How about, in a formal wedding invitation…

    at one-thirty in the afternoon?

    • Rule 12 of Writing Numbers states, “Normally, spell out the time of day in text even with half and quarter hours. With o’clock, the number is always spelled out.

      Examples:
      She gets up at four thirty before the baby wakes up.
      The baby wakes up at five o’clock in the morning.

      Therefore, “at one thirty in the afternoon” is correct. You may find that some of the wedding websites disagree with this. Our rule is based on Chicago Manual of Style’s rule 9.38. Wedding invitations sometimes have their own sets of rules and they are not always the same as rules for formal writing.

  7. Matt says:

    Which is correct:
    A) We require a staff of seven to ten employees.

    or

    B) We require a staff of 7-10 employees.

    Thank you.

    • Either of your choices might be acceptable, depending on one’s policy. Our Rule 2 of Writing Numbers states, “Be consistent within a category. For example, if you choose numerals because one of the numbers is greater than nine, use numerals for all numbers in that category. If you choose to spell out numbers because one of the numbers is a single digit, spell out all numbers in that category.” Therefore, either sentence is grammatically correct. If you choose to go with the numerals, use a hyphen or an en dash to separate them.

      We require a staff of seven to ten employees. OR
      We require a staff of 7–10 employees.

  8. JP says:

    Which format is correct for the numbers in each of the two following lines?

    Twenty five of the students OR Twenty-five of the students
    Twenty-five students OR Twenty five students

    I was taught that numbers like twenty five are hyphenated if used as an adjective as in Line 2 but not hyphenated when used as a noun as in Line 1.

    • The number twenty-five is always hyphenated regardless of how it is used in a sentence. You are most likely thinking of the rule from our Hyphens with Numbers blog, which states, “When you’re combining two or more words to form a compound adjective in front of a noun, put hyphens between these words. When numbers are used as nouns, don’t use a hyphen.”

      Examples:
      An 18-inch monitor is too big for my desk.
      Anthony swung his five-pound hammer.
      Anthony’s hammer weighs five pounds.
      The room was 17 feet long.

  9. Rachel says:

    Which format would be correct here:

    Griddles plates are available in different thicknesses ranging from thin plates (three-eighth inch to three-fourths inch) to thick plates (one-inch to one-and-one-half inch)….

    or should this be written numerically?
    …thin plates (3/8-inch to 3/4-inch) to thick plates (1-inch to 1-1/2-inch)….

    Normally I follow the under ten write it out rule, but with the fractions I am not sure! Thanks for your advice!

    • Rachel, while you may have thought you were asking a relatively simple question, this is really a complex lesson in writing numbers. The first complexity is that your example contains both simple fractions and a mixed fraction. Rule 3 of Writing Numbers says “Always spell out simple fractions and use hyphens with them.” This would lead us to write three-eighths inch and three-fourths inch. Rule 4 says “A mixed fraction can be expressed in figures unless it is the first word of a sentence,” which would allow us to write 1 1/2 inches in figures rather than write it out. Let’s bring in Rule 2, which cautions us to “Be consistent within a category.” Therefore, we should either write them all out in words or express them all in figures. Whether a hyphen is placed before the word “inch” or not depends upon whether these are compound adjectives or simple measurements. Our guess is that you have simple measurements within your parentheses which, if written out, are really saying “. . . thicknesses ranging from thin plates (three-eighths of an inch thick to three-fourths of an inch thick)” rather than in compound adjective form “. . . thicknesses ranging from thin plates (three-eighths-inch thick plates to three-quarters-inch thick plates).”

      To be fully grammatically correct, we recommend “Griddle plates are available in different thicknesses ranging from thin plates (three-eighths of an inch to three-fourths of an inch) to thick plates (one inch to one and one-half inches).” Also acceptable would be “Griddle plates are available in different thicknesses ranging from thin plates (3/8 inch to 3/4 inch) to thick plates (1 inch to 1 1/2 inch).”

      • Will says:

        When referring to something that is more than one inch but less than two inches, do you pluralize the word “inch”?
        Example: “The worm is 1 1/2 inch long.” or “The worm is 1 1/2 inches long.”

      • friendlyadvice says:

        I would hyphenate “3/8 inch”, “3/4 inch”, etc. in this sentence:

        “Griddle plates are available in different thicknesses ranging from thin plates (3/8 inch to 3/4 inch) to thick plates (1 inch to 1 1/2 inch).”

        “3/8 inch”, e.g., is an adjective, describing “thin plates”. The sentence follows the form, “We sell many things, from sunscreen (over-the-counter and prescription) to costumes (scary, modern, and old-fashioned).” The parentheticals contain adjectives that describe the nature of the thin plates, and the nature of the thick plates. “1 inch” is not a kind of noun that commonly references a type of thick plate; it’s an adjective, referring back to the thick plates. I.e., we’re talking about “1-inch thick plates”, if “thick plates” is presumed to be an industry term (we could separately discuss “1-inch-thick plates, if we did not presume this). Therefore, even if I moved the adjective to a parenthetical, I would preserve the hyphenation of it.

        E.g.: “Griddle plates are available in different thicknesses ranging from thin plates (3/8-inch to 3/4-inch) to thick plates (1-inch to 1 1/2-inch).”

        Also, for what it’s worth, I would avoid “1 1/2” if I couldn’t properly format the “1/2” part (by using a superscript 1 and a subscript 2). If you’re under the constraints of awkward word-processing software (for instance, within these comment boxes), I would just write “1.5-inch”.

        1 1/2 is a bad construction for the following reason:

        When most people read “15 1/2-inch rods”, it means “fifteen half-inch rods”.

        But, if you adopt the standard of writing “1 1/2” as an adjective, then… “15 1/2-inch rods” could mean “fifteen-and-a-half-inch rods”, OR it could mean “fifteen half-inch rods”. You can’t tell, anymore, because your punctuation practices are conflicting. Now you force the reader to wander around in search of context clues — in my view, it’s much better to avoid the confusion by using decimal points or full words, if you lack the ability to attractively format your numbers.

        • As we stated to Rachel, “Our guess is that you have simple measurements within your parentheses which, if written out, are really saying ‘. . . thicknesses ranging from thin plates (three-eighths of an inch thick to three-fourths of an inch thick)’ rather than in compound adjective form ‘. . . thicknesses ranging from thin plates (three-eighths-inch thick plates to three-quarters-inch thick plates).’ Since the measurements were not compound adjectives, we did not use any hyphens in 3/8 inch, etc.

          We did not think that anyone would be confused when reading 1 1/2 inch, therefore we did not consider it “bad construction,” although 1.5 inches is also acceptable. Since Rachel specifically used that term, we answered the question as asked.

  10. Al says:

    Which is correct to say
    He is a 3-year old baby.
    He is a 3-years old baby.
    He is a three-year old baby.
    He is a three-years old baby.
    He is a three year old baby.
    He is a three years old baby.

  11. kelse says:

    is it ive done girl scouts for five-years or five years

    • Since the word five is not a compound adjective, do not hyphenate. Also, the word Girl Scouts is a proper name and should be capitalized.
      I’ve done Girl Scouts for five years.

  12. jennifer says:

    When you are capitalizing hyphenated numbers in a title, does the second number appear in lower case?

    Twenty-first commencement exercise or/
    Twenty-First Commencement Exercie

    • The Chicago Manual of Style’s Rule 8.159, Hyphenated compounds in headline-style titles, states, “Capitalize the second element in a hyphenated spelled-out number (twenty-one or twenty-first, etc.) or hyphenated simple fraction (two-thirds in two-thirds majority).”

      Twenty-First Commencement Exercise

  13. Ingrid says:

    Well, but the hyphenating rules doesn’t explain why it would be 5-foot instead of 5-feet in the first place, i.e. the use of the plural instead of the singular.
    I’m assuming it’s because the noun is considered one single mass rather than individual units, but how is that explained in grammatical terms?

    • You are writing about a singular object, which consists of a compound adjective in front of a noun, such as a 5-foot fence, a 3-pound hammer, or a 2-inch hem. It is different if you are referring to the measurement itself such as 3 feet tall, 10 pounds lighter, or 2 inches shorter.

  14. Kimber says:

    I am writing instructions for a kit….

    Which is correct?

    “This area needs to be a 2- to 3-foot section…”
    “This area needs to be a 2 to 3-foot section…”
    “This area needs to be a two- to three-foot section…”
    “This area needs to be a two-foot to three-foot section…”

    Or is there another way that I have missed?

    • The Chicago Manual of Style’s rule 7.84 says, “When the second part of a hyphenated expression is omitted, the hyphen is retained, followed by a space.” Repeating the word foot is not required.
      Therefore, write either “a two- to three-foot section” or “a two-foot to three-foot section.”

      However, we are not sure we are understanding you correctly. Saying “a two- to three-foot section” implies only one linear dimension. An area consists of two dimensions. If that is the case, then you would need to write “This section needs to measure two feet by three feet” or something to this effect.

  15. Joseph says:

    This website is awesome.

  16. Christine says:

    I am wondering how this would work with regards to GHz.

    Should I be writing 2.4 and 5 GHz bands
    or should I be using hyphens? I find them quite disturbing in this context.

    • Our blog Hyphens with Numbers contains this general rule: when you’re combining two or more words to form a compound adjective in front of a noun, put hyphens between these words. If you followed this rule, you would write I am going to use the 5-GHz band (5-GHz is a compound adjective modifying the noun band). On the other hand, if you wrote The frequency I’m going to use is 5 GHz there is no hyphen since 5 GHz is not a compound adjective in this context. That being said, while we are not experts on radio frequencies or bandwidths, we have not seen hyphens used in this particular subject area, even when clearly being used as a compound adjective. You are probably safe following the standard practices being set here.

  17. Michelle says:

    What is the correct hyphenation for the following sentence?

    The sheets I purchased are 400 thread count.

    Would the hyphen just be placed after 400? (i.e. 400-thread count)

    Thanks!

    • Our Rule 4 of Hyphens says, “Generally, hyphenate between two or more adjectives when they come before a noun and act as a single idea.” Therefore:
      I purchased 400-thread-count sheets. OR
      The sheets I purchased have a 400 thread count.

    • friendlyadvice says:

      And, to answer your question a little more directly, in your proposed sentence, it would be this:

      (1) The sheets I purchased are 400-thread-count.

      …just as if you had written…

      (2) The sheets I purchased are large.

      …except the adjective “large” is replaced with “400-thread-count”.

  18. Logan D says:

    Great site! I learned so much.

    Would it be a “24 unit complex can be built in 9 days” or a “24-unit complex can be built in 9 days?”

    Thanks!

    • We are glad you find our website useful. Our Rule 4 of Hyphens says, “Generally, hyphenate between two or more adjectives when they come before a noun and act as a single idea.” Therefore, write “A 24-unit complex can be built in 9 days.”

  19. Joanne says:

    I’m wondering if I’m hyphenating correctly here:

    “You can purchase a one-, three-, or seven-day pass to the amusement park.”

    (I swear, I spend more time looking up how to properly hyphenate things…I wish it wasn’t so hard for me.)

    • Yes, you hyphenated correctly.

      • Alan S. says:

        First, let me say I love and value your website. Thank you very much for your efforts. To the person who asked about one-, two- and three-day passes, yes, it’s correct. How, I much prefer your suggestion of adding the noun: one-day, two-day and three-day passes. The hanging hyphen looks like a mistake. One man’s opinion

  20. Debbie F says:

    How would this be hyphenated?

    “The 5 day time frame is for adding the case…”

  21. Cindy says:

    I’m working on a product catalog. Talk about consistency… each supplier has a different way to doing things with their own rules. I’m working on a style book so we can be consistent. Please advise me on the following.

    3″-wide laminated board
    3″ wide laminated board

    Thank you!

  22. Genia says:

    Thank you for your guidance, which has been very helpful to me.

    Here is a question regarding a somewhat related subject having to do with abbreviating measurements:
    Which form is correct?
    1. The property has a 2,000 sq.ft. building and a 5,000 sq.ft. building.
    2. The property has a 2,000 sq ft bullding and a 5,000 sq ft building. (APA style)

    I’ll appreciate your help. Thank you!

    • Our Rule 4 of Hyphens says, “Generally, hyphenate between two or more adjectives when they come before a noun and act as a single idea.” In your sentence, the measurement is a compound adjective describing the noun building. You may want to avoid using abbreviations in formal writing.

      The property has a 2,000-square-foot building and a 5,000-square-foot building.

      If you use abbreviations, we simply recommend that you remain consistent in the style guidance that you choose. You certainly may choose to follow APA style. We side closer to guidance from The Chicago Manual of Style, which would recommend The property has a 2,000 sq. ft. building and a 5,000 sq. ft. building. Note that CMOS uses a period when abbreviating English units and does not use hyphens with abbreviated units even in adjectival form.

      • Brenda C Freiheit says:

        You wrote:
        “The property has a 2,000-square-foot building and a 5,000-square-foot building.
        If you must use abbreviations, use periods with abbreviations that end in a lowercase letter.”

        I have always suggested that my husband use the format you described above, when he writes reports. However, he says it is typically common in his company standards to abbreviate measurements (even when adjectives). So then, I recommended he then write it as “2,000-sq.-ft. building and a 5,000-sq.-ft. building.” However, he says that he believes the company standards are to only hyphenate between the 2,000 and sq., but not between the sq. and ft., when used as an adjective. My argument is that such a format would imply it is a 2,000-sq. ‘ft. building.’ (What is a ‘foot building?’) Surely this is not a grammatically correct way to write this, and I challenge this. The only way I’d see that it would be acceptable without the second hyphen is if the words sq. and ft. were pushed together without a space: “a 2,000-sq.ft. building.” What are your thoughts about this? Would pushing those two abbreviations together make it any more acceptable if he insists on omitting the second hyphen?

  23. ArangoA says:

    If I’m using Hyphens with numbers, but in a “non-traditional” way, I don’t know which rule to follow.
    Example: …comparing 30 to 90-day mortality…
    Should I also hyphenate after 30? It would be:…comparing 30- to 90-day mortality…
    Thank you!

    • This is known as a suspensive hyphen or suspended hyphen. It is used when hyphenated words occur in sets of two or more and the first or second part of the compound is only used once. Therefore, use a hyphen after 30.
      comparing 30- to 90-day mortality…

  24. Sheri says:

    Would you stay consistent throughout the paragraph for the category (measurements) or transition back to written numbers in the last sentence?

    The new 6-foot 3-inch tall, 342-inch-diameter tank will be located 7 feet in front of an existing tank. A 12-foot-tall, 13-foot-wide by 25-foot-long wall will be installed to meet the two-hour fire resistance requirement. The wall is required to be one foot from the tank and five feet from existing walls.

    • Deciding whether to write numbers as numerals or as number words is a matter of style. We recommend using a consistent style throughout your writing.

    • Brenda C Freiheit says:

      Sheri wrote: “The new 6-foot 3-inch tall, 342-inch-diameter tank will be located 7 feet in front of an existing tank. A 12-foot-tall, 13-foot-wide by 25-foot-long wall will be installed to meet the two-hour fire resistance requirement. The wall is required to be one foot from the tank and five feet from existing walls.”

      I would have written that similarly, except using a hyphen between inch and tall since it is still part of the adjective describing tank. “The new 6-foot-3-inch-tall, 342-inch-diameter tank…” (the same way you did on 12-foot-tall), and I also would add a hyphen between 6-foot and 3-inch-tall (“6-foot-3-inch-tall…,”) to keep it all as one measurement and to remove the consideration that the the height may be either six feet or three inches.

      In the next sentence, where you have “The new 13-foot-wide by 25-foot-long wall…,” I would make that all one big hyphenated adjective: “The new 13-foot-wide-by-25-foot-long wall will be… .” The reason I would do that is because “by” is not a normal part of the sentence, but a part of the adjective. However, that guideline would be different if you were to write, “I put the new 13-foot-wide table by (beside) the 25-foot-long wall.” In that case, the word “by” is another part of the sentence, and not an adjective describing the measurement.

      My husband writes reports with dimensions in them for his job, and I help proofread them for him. While not proclaiming to be an authority on writing, those are just some of the standards I have adapted, whether or not they are right? I would welcome the advice on whether or not that is correct.

      • We agree that “tall,” plus all the words preceding “wall” should be hyphenated.

      • Brenda C Freiheit says:

        I forgot to mention that when you feel too many words are strung together with hyphens to form a long adjective, another way to convey the same meaning would be to turn the sentence around to omit some of the hyphens.

        So, Instead of writing, “A 12-foot-tall, 13-foot-wide-by-25-foot-long wall will be installed to meet the two-hour fire resistance requirement,” it might be easier to instead write, “To meet the two-hour fire resistance requirement, a wall will be installed. The wall will have a height of 12 feet, width of 13 feet, and length of 25 feet.”

        Another option might be: “To meet the two-hour fire resistance requirement, a wall will be installed with the following dimensions: (Then use bullet points.) * height of 12 feet *width of 13 feet *length of 25 feet

        Another way to break down the dimensions would be to write: “To meet the two-hour fire resistance requirement, a wall, with a 12-foot height, 13-foot width, and 25-foot length, will be installed.”

        I think any of these options would be considered acceptable alternatives, but I was curious as to what data.grammarbook would have to say about them? I have these same types of questions all the time!

      • Your examples are fine.

  25. Marvelyn says:

    I am editing a book for someone and have a couple of questions.
    1. As a young Christian it surprised me that I did not meet other evangelical believers during that six week trip. (SHOULD SIX WEEKS BE HYPHENATED?)

    2. This had been my third large Summer of Service in four years’ time. (SHOLD FOUR YEARS’ BE HYPHENATED?)

    3. Also, we were about to start a yearlong music team with eight people, which Rolf would lead and I would participate in. (SHOULD YEARLONG BE 1 WORD OR 2? IF 2, SHOULD IT BE HYPHENATED?)

    • Our blog post Numbers as Adjectives says, “Generally, hyphenate between two or more adjectives when they come before a noun and act as a single idea. This rule can also be applied when a number and a measurement unit taken together form an adjective, that is, when they describe another object.” We also would point out that the sentence begins with a dangler. Therefore, write “As a young Christian, I was surprised that I did not meet other evangelical believers during that six-week trip.”

      In your second sentence, the word time is unnecessary and so is the apostrophe after the word years. No hyphen should be used. If Summer of Service is the formal title of a program, it may be capitalized. If not, it should be lowercased. Write “This had been my third large Summer of Service in four years.”

      The word yearlong is one word, however your final sentence could be rewritten as follows: “Also, we were about to start a yearlong music team, in which Rolf would lead and I would participate, along with six other people.”

  26. Rachel says:

    Thank you so much for this post.

    I need to specify that a drug in a study was administered three times a week instead of the usual daily administration. Is the following correct?

    “Drug X three-times weekly demonstrated a 20% reduction in…”

  27. Peggy says:

    Can you confirm that this construction would not get a hyphen (because “three quarters” is not a compound modifier in this case)?
    “…more than three quarters of our staff…”

    • The Chicago Manual of Style’s rule (9.14) says, “Simple fractions are spelled out. For the sake of readability and to lend an appearance of consistency, they are hyphenated in noun, adjective, and adverb forms…”

      “…more than three-quarters of our staff…”

  28. Beth Haden says:

    I’m proofreading an art book, and there are many references to photos’ measurements, e.g., “8 by 10-inch” or “3 by 5-inch.” Am I right to insert a hyphen after the 8 or the 3? Thanks!

    • If the measurement is an adjective phrase in front of a noun, the entire adjective phrase should have hyphens.

      8-by-10-inch photo
      3-by-5-inch photo

      Do not use hyphens if the measurement is written “The photo pictured is 8 by 10 inches.”

  29. Maria says:

    Should I use a dash, not a hyphen, between centuries and decades, for example, “in the 16th–17th centuries” and “the 1920s–30s”? Or is the n dash used between numbers only (without -th or -s etc.)? Thanks!

    • The en dash is used by many for periods of time when you might otherwise use to. Others use hyphens. Below are various methods for conveying time spans.

      16th–17th centuries
      16th-17th centuries
      1920s–1930s
      1920s–’30s
      1920s-30s

  30. C says:

    I’m trying to get the gist of this through examples. Is this correct?

    The ocean was one thousand feet deep.
    The one-thousand-foot-deep ocean was cold.
    The man was six feet tall.
    The six-foot-tall man was two hundred pounds.
    The two-hundred-pound, six-foot-tall man was scary.
    The car was was four feet wide.
    The four-foot-wide car was rusty.

  31. Josie says:

    What is the correct way to express the following:

    I have to work two, eight hour shifts this week? Is it correct to place a comma after two?

  32. Jaynie says:

    Is this correct usage of hyphens:
    The entire complex was surrounded by a 30-foot high brick wall.

    Or should it be a 30-foot-high brick wall?
    Thanks so much!

  33. Sonya says:

    In deposition transcripts, people often omit the word “hundred” or “thousand” after the first number said, and I’m unsure of how to write that sentence.

    “I have between 5 and 15,000.”

    A better way to say it would be “I have between 5,000 and 15,000,” but of course in a deposition, I can’t add the “thousand” after the 5 since it has to be verbatim. I’d rather not write the numbers all out because then it makes it difficult for attorneys to search for specific numbers within a transcript, and it also would not be consistent with the rest of the transcript. Would it be acceptable to write “I have between 5- and 15,000”?

    Thanks for your help!

    • This appears to be a good opportunity to use brackets. Brackets are often used within quoted passages to indicate material added by someone else. You could type “I have between five [thousand] and fifteen thousand …” It seems like attorneys should be able to search for written-out numbers as well as numerals, but you could probably also write “I have between [5,000] and 15,000 … “

  34. Tyler says:

    I’m trying to write the following sentence:

    Out back there is a twenty-by-forty foot Martinique-style swimming pool and a 500-square-foot pool house.

    This is for a novel, and I assume it is more appropriate to write the numbers out rather than using numerals. Is that correct in both cases in this sentence? If so, how do I use hyphens when both of them are written out?

    Thanks so much for your help! This is an excellent website.

    • Spelling out numbers vs. using figures is largely a matter of writers’ preference. Consistency is the key. Don’t forget the hyphen between “forty” and “foot.”
      Out back there is a twenty-by-forty-foot Martinique-style swimming pool and a five-hundred-square-foot pool house. OR
      Out back there is a 20-by-40-foot Martinique-style swimming pool and a 500-square-foot pool house.

  35. Ethan says:

    I’m accustomed to hyphenating as follows:
    You son is growing up! Yes, he’s a four-year-old.
    But from what I gather from the above rule, four-year-old is considered a noun and therefore is not hyphenated. Which is correct?
    Thank you so much.

  36. wendy says:

    I am translating some literature for a trailer manufacturer
    and they talk about 2 or 3 axle trailers
    do I write
    2 or 3-axle trailer
    2- or 3-axle trailer
    2 or 3 axle trailer

    or what about a 3 metre trailer
    3-metre trailer?

    50-millimetre-thick softwood – no hyphens?

    I was under the impression the English language was using less hyphens, yet these rules seem to imply more?
    Thanks for your comments

    • In your examples, the measurements are compound adjectives describing nouns. Hyphens are required.
      2- or 3-axle trailer
      3-metre trailer or 3-meter trailer (American English)
      50-millimetre-thick softwood or 50-millimeter-thick softwood (American English)

  37. Rebecca says:

    What about these two sentences:

    The candidates completed a one hour written test.
    The test was followed by a one hour interview.

    Thank you!

    • One-hour is used as a compound adjective in your sentences. Therefore, use a hyphen.
      The candidates completed a one-hour written test.
      The test was followed by a one-hour interview.

  38. Meg says:

    What is the correct way using the Chicago Style to write ‘1,500’ in the sentence, “I spent over 1,500 hours researching material?” Should I spell it out, hyphenate, or use numerical? Thank you for your time.

    • The Chicago Manual of Style’s Rule 9.2 says, “In nontechnical contexts, Chicago advises spelling out whole numbers from zero through one hundred and certain round multiples of those numbers.” In addition, their Rule 9.4 states, “Any of the whole numbers mentioned in 9.2 followed by hundred, thousand, or hundred thousand are usually spelled out (except in the sciences)—whether used exactly or as approximations.”

      I spent over fifteen hundred hours researching material.

  39. CD Demetrious says:

    Are these two correct?: 1) Twenty-plus years experience 2) Twenty-plus year professional Thank you!

    • An apostrophe is needed after years: Twenty-plus years’ experience. Twenty-plus is a compound adjective describing the noun years. (Or it could simply be written as Twenty-plus years of experience.)

      A second hyphen is required in the phrase twenty-plus-year professional since twenty-plus-year is the compound adjective describing the noun professional.

  40. enah says:

    How do you write this one.

    Is it like this: The patient has a 4- to 5-month history of pain.

    or The patient has a 4 to 5-month history of pain.

    and what is the general rule for that.

    Thank you

    • The Chicago Manual of Style’s rule 7.84 says, “When the second part of a hyphenated expression is omitted, the hyphen is retained, followed by a space.” Therefore, write:
      The patient has a 4- to 5-month history of pain. OR
      The patient has a four- to five-month history of pain.

  41. John says:

    How would I write this out numerically?

    Complete this job using ten feet of one, four inch conduit?

    Specifically the “one, four-inch” part.

    At work, I keep seeing management write it out as 1-4″ conduit. That just doesn’t look right to me. To me, that reads, “one through four”. I wanted to write it like this: (1) 4″ conduit. Or: “…one, four-inch conduit.

    Thanks!!!!

    Should there be a hyphen between four-inch?

    • There should be a hyphen between four-inch or 4-inch and no comma after one.
      Complete this job using ten feet of one four-inch conduit.
      OR
      Complete this job using one 10-foot length of 4-inch conduit.

  42. Nancy Adams says:

    I’m editing a ms, and can’t find the rule in the Chicago Manual.

    “He was about five-eight.”

    Is the hyphen here correct? According to Chicago, if I included “foot,” it be open: “He was five foot eight,” but I can see the logic of including the hyphen in a sentence without the unit of measurement.

    Thanks!

  43. Frank Sellers says:

    What about a range before a noun?

    Is it:

    “The car is 10 to 15 feet away.”

    or:

    “The car is 10-to-15 feet away.”

    ???

    Thanks!

  44. TJ says:

    If there are multiple adjectives. Writing a recipe. “1/4-inch-thick patties”?

  45. Tawna Petersen says:

    How would this be hyphenated?

    Five- to six-year-olds will have a lot of questions. Or should I put five- to six-year-old students?

    Thanks!

  46. CX says:

    Ok, in a document that requires that numbers be written both numerically and spelled out, how should the phrase be constructed?

    Instead of ‘six-foot fence’, I need to also insert ‘(6)’.

    six (6)-foot fence
    six-foot (6) fence
    six(6)-foot fence

  47. Debby says:

    Why can’t I ever decide if these need hyphens?

    Q. 4 1/2 feet is — the front face of the drawer was 4 1/2 feet wide?
    A. Yes.
    Q. And then it was 3 feet deep, meaning the drawer would go back into the cabinet 3 feet approximately?
    —-
    Q. How big was the drawer?
    A. I’d estimate probably 4 1/2 feet long and probably 3 feet wide.
    Q. How tall?
    A. Probably 14 inches tall.
    Thanks for your wisdom!

    • There are no compound adjectives in your sentences, therefore no hyphens are required. Note the difference between these two sentences:

      The drawer is 14 inches tall.
      It is a 14-inch-tall drawer.

  48. Andrea says:

    I’m working on a settlement agreement for a temporary easement and am trying to word the following agreement terms correctly. I’m having the most trouble with the tree stump language, as there are 4 tree stumps, but 2 of them have the same approximate diameter and if I say that there are 4, where/how would I reword that correctly?:

    “In addition, Grantee agrees, at the time of construction, to the following:

    To fill an approximately 8-by-6-foot-wide and 3.5-foot-deep hole created by Grantor to locate existing underground utilities; to do a one-time clearing of existing overgrown vegetation near said utility-locate hole, but not to clear any future overgrown vegetation during the term of this Temporary Construction Easement unless, in Grantee’s sole determination, such material restricts safe passage through the easement; and to grind an 18-inch, two 24-inch, and a 36-inch approximate diameter tree stump.”

    • The meaning of the paragraph seems clear to us. However, legal documents often have their own sets of rules. We recommend consulting either The Bluebook: A Uniform System of Citation, published by the Harvard Law Review Association or the ALWD Citation Manual: A Professional System of Citation, prepared and published by the Association of Legal Writing Directors and Darby Dickerson.

  49. Linda Cauble says:

    how do I hyphenate 11 year 2 month payoff

  50. Sandra says:

    Thanks for your website – I find it really helpful!
    I have a question about hyphenation with multiplication signs. In the phrase ‘a 30 x 50 cm sheet was used’, should the hyphenation be ‘a 30 x 50-cm sheet was used’ or ‘a 30- x 50-cm sheet was used’? And what about ‘a 30 x 50 x 20 cm box was used’ or ‘a 30 x 50 x 20 cm high box was used’? If I substitute ‘by’ for the multiplication sign (in my mind!), I guess I would write ‘a 30- x 50- x 20-cm-high box’. Is this correct?

    • To simplify the situation, we recommend that these descriptions be reworded to “a sheet measuring 30 x 50 cm was used,” “a box measuring 30 x 50 x 20 cm was used,” and “a box measuring 30 x 50 x 20 cm in height was used.”

  51. Angela says:

    What about in terms of warranties? Would you hyphenate 5-year warranty?

  52. Michael D. says:

    Your website says:
    Incorrect: 300—325 people

    Incorrect: 300 – 325 people

    Correct: 300-325 people

    I agree an em-dash is incorrect, and putting spaces around a hyphen is incorrect, but I am not aware of any style guides that say it’s ok to express a number range with a hyphen. An en-dash is always required. If you can point me to a reputable style guide that contradicts this, I’d like to know about it.

    • The Associated Press Stylebook, certainly a reputable resource, uses a hyphen under its heading “ranges” where you can find the example “A pay increase of 12-15 percent.” AP does not even acknowledge that the en dash exists.

      In preparing the 11th edition of The Blue Book of Grammar and Punctuation, we thought long and hard about hyphens vs. en dashes and concluded that it is more a policy matter for publishers to worry about, and not within the scope of what we wished to emphasize in our book.

  53. Ellie says:

    I need help with hyphens and numbers for my term report project. My prof mentioned that numbers from 1 to 10 should be written as words (e.g.: 1 = one, 2 = two, etc) and larger number after the 10th should be written as numbers. But she forgot to mentioned about the hyphens with number sections. I just wanted to ask you if I am using the following correctly:

    1. …. a minimum of one-to-three years of work experience
    2. a completion of one-to-four years college programs…
    3. a completion of eight-month to one-year post-secondary certification….

    Are these the correct format? Or I should change them to words format?

    Thanks for your help!

    • Your third sentence seems to be missing a word. If you mean “an eight-month to one-year certificate” then the hyphens are correct. In your first two sentences, no hyphens are required or advised.

  54. Justine Holland says:

    Trying to settle controversy. Which is correct:
    2-1/2-year-old or 2 1/2-year-old?

    • No hyphen is necessary within the mixed fraction “2 1/2.” Therefore, write “2 1/2-year-old.” For readability in email documents, you could also cut and paste “½” from a word processing program.

  55. Andi Suprianto says:

    Which is the correct way or writing this sentence:

    THIS RIVER IS 20-METER DEEP or
    THIS RIVER IS 20-METERS DEEP

    • As the blog states, when numbers are not used as compound adjectives preceding nouns, don’t use a hyphen. We do not recommend writing in all caps. Therefore, write the following:
      This river is 20 meters deep. OR
      This river is twenty meters deep.

  56. diana says:

    How do I write My daughter is 5 feet and 1/4″ tall? Is that correct?

    • If we had to mention the quarter-inch, we would recommend writing “My daughter is five feet and a quarter-inch tall.” However, it seems that measuring a person’s height in quarter inches is usually reserved for infants. We prefer “just a shade over five feet tall.”

  57. Susana says:

    How do I write 2 years- 6month-old?
    Thanks

    • The simplest way to convey the same meaning is to write it out.
      Examples:
      Her daughter is two and a half years old. OR
      She has a two-and-a-half-year-old daughter.

  58. Renee says:

    Cut chicken into 1½ inch pieces

    hyphen needed?

  59. Melanie says:

    I have a question relating to hyphens with numbers, sort of. We know that we would say “40-plus days spent reading” because 40 and plus form a compound modifier, but is there any rule for not using the plus symbol instead? “40+ days spent reading”?

    We’re planning to ban it as part of our house style, but I’d love to be able to cite a rule that supports our reasoning.

    Thanks!

    • AP Stylebook seems to agree with you. The following question and answer is from their “Ask the Editor” section:

      Q. Is it okay to use the plus sign when indicating more than. For example, “He has 20 years of experience.”? – from Atlanta , Ga. on Mon, Mar 18, 2013
      A. AP would spell it out: 20-plus years of experience.

  60. Stacey says:

    In a nonfiction book, is it correct to say, “five-hundred-pound throne” or “500 lb. throne”?

    • Spelling out numbers vs. using figures is largely a matter of writers’ preference. Consistency is the key. Compound adjectives require hyphens whether they are expressed as words or numerals. We prefer writing out pound rather than using the abbreviation. Therefore, we recommend the following options:
      five-hundred-pound throne
      five hundred-pound throne
      500-pound throne

  61. Pat McCune says:

    What is the correct way to abbreviate square foot or square feet? I have seen it written a dozen different ways. sq ft, sq. ft., sft, ft2 (with 2 in superscript), SF

  62. Cathy says:

    21 X 21-foot section. Is this correct?

  63. Stuart says:

    Here’s one with a scientific bent. The SI (International System of Units) guide says to write “a 5 kg sphere” instead of “a 5-kg sphere”. I can accept this. But which of these is then correct: “A 10-m-long wire” or “A 10 m-long wire”? The latter looks odd to me.

    • According to The Chicago Manual of Style, hyphens are never used between the numeral and the abbreviation or symbol, even when they are in adjectival form. Therefore write 10 m long wire.

  64. Laura says:

    I’m writing a brochure and I’m not sure how to punctuate this…”engage in 30- to 40-minute discussion with panelists” or “engage in 30 to 40-minute discussion with panelists”? The ad agency wrote the first one, but I think the second looks better.
    Thanks for your help. This is a great resource!!

  65. Liz says:

    Which is correct?
    The last 4-digit of your phone number is the default password.
    The last four digits of your phone number is the default password.
    The default password is the last 4-digit of your phone number.
    The default password is the last four digits of your phone number.

    Thank you. This is very important.

  66. Mary says:

    I’m creating a poster for an event. Do I need to hyphenate Three-Day or can it go without?

    A Three Day Celebration!

    • Since Three-Day is a compound adjective describing the word Celebration, we would ordinarily recommend using a hyphen. However, poster headings promoting events such as the one you describe often delete such hyphens to avoid running two short, simple words together. The thinking is that Three-Day looks cluttered and too complex.

  67. Melody says:

    I’m struggling with a sentence that refers to a range between two compound adjectives: “This is especially true of a longer, fifteen to twenty-one-day cleanse.” If I were writing them separately, I would say, “fifteen-day cleanse” and “twenty-one-day cleanse.” How should one correctly punctuate the range? Thank you!

  68. Stan says:

    I am writing a recipe in which I have to convert inches into centimeters in parenthesis and it makes things complicated. What do you think of these? Are they correct?

    – “… into a circle of roughly 10 inches (25 cm) in diameter and about 1/2 inch (1 cm) thick.

    Should there be a hyphen after 10 and 25 or just 1/2 and 1?

    – “Using a 2-inch (5-cm) round cookie cutter,…” I guess the right way would be “2-inch-round cookie cutter” but the (5-cm) makes it complicated. What do you think? Many thanks in advance!

    • No hyphens are required for “10 inches” or “25 cm” because they are not used as adjectives. In accordance with The Chicago Manual of Style, write 1/2-inch (1 cm) thick, because hyphens are used when units are spelled out in adjectival form, but not when abbreviated.Therefore, write 2-inch-round (5 cm) cookie cutter.

      • Stan says:

        Many thanks for the reply. I have an additional question about the second line. If I wanted to add “plain”(as opposed to fluted), would this be the correct way to write it:

        “2-inch-plain-round cookie cutter”

  69. Deb Tarniw says:

    Which is correct?

    The highway consists of 12-foot-wide lanes in both directions.

    The highway consists of 12-foot wide lanes in both directions.

    The highway consists of 12-feet wide lanes in both directions.

    The highway consists of 12-feet-wide lanes in both directions.

  70. Sarah G says:

    Lots of recipes and different ways to hyphenate things:

    4 (6 ounce) New York strip steaks, about 1-inch-thick
    OR
    4 (6-ounce) New York strip steaks, about 1 inch thick

    “Cut about 8 (1/4-inch slices) from…”
    OR
    “Cut about 8 (1/4 inch slices) from…”

    Lastly, is this correct?
    “…shape about 1 1/2 inches in diameter.”

    …and why? My boss will want the explanations.

    Thank you!!

    • * Four 6-ounce New York strip steaks, about 1 inch thick

      * Cut about eight 1/4-inch slices from …

      * Third example is all right.

      The explanations are contained in the above blog post: simply determine whether the numbers are used as part of compound adjectives.

  71. Dave Fernie says:

    We use a valve that has three inputs and one output.

    Should this be written as a ‘3 to 1 valve’ or a ‘3-to-1 valve’?

  72. Amy says:

    which is correct

    6-cars or six cars

  73. Ed M says:

    I recently saw a reference to wrench that fits a nut 3/4 of an inch wide as:
    “3/4 of an inch wrench”.
    First, I’m wondering if my use of “of an” was proper, and are there rules for proper usage?
    Second, I presume 3/4 and inch make up a compound adjective modifying wrench, so it should be:
    “3/4-inch wrench”. Yes??

  74. Ted A says:

    In a report to our Board of Public Works, we often have measurements with feet and inches and in the cases where it appears correct to use a hyphen, is a hyphen also used between the feet and inches? As in:

    ACME requests permission to place a 41-foot-11-inch high wood monopole…

    Also, in cases where it appears correct not to use hyphens, is a space just used between them also? As in:

    ACME requests a variance from the maximum height limitation of 5 feet 6 inches per the AGF Ordinance …

    • Yes. You are writing a compound adjective. Write “ACME requests permission to place a 41-foot-11-inch-high wood monopole …” Your second example is correct.

  75. Beth says:

    Which is correct: “one-hundred-twenty-day deadline” or “one hundred twenty-day deadline”? My instinct is the second example, because you wouldn’t hyphenate “one hundred twenty.”

  76. Tina says:

    I’m just wondering which is correct:

    Who would think 15-and 16-year-olds would be self-conscious?

    Who would think 15 and 16-year-olds would be self-conscious?

    Thanks in advance!

  77. Melanie says:

    Normally a “six-month visit” is a visit that lasts six months, as in “I made a six-month visit to France.”

    But I have two cases where I’m not sure whether “month” should be singular or plural.

    Case #1: “Patients will be have follow-up appointments six months and twelve months after surgery. At the six-month(s)appointment x-rays will be taken.”

    Case #2: “Infants will be evaluated when they are six months and twelve months old. At the six-month(s) evaluation they will be weighed.”

    In both of these cases I’m not convinced that “six-months” is an adjective because it doesn’t clearly modify the noun following it. The first case is an appointment that takes place six months after surgery, not an appointment that lasts six months. The second case is an infant who is six months old, not an evaluation that lasts six months.

    In these two cases should it be “month” or “months,” and WHY? I’m included to use “months” in both cases but I don’t know the applicable grammar rule. Is there one?

    Thank you very much!

    • We see your point and cannot see any problem with “months” if you have no option to rewrite. Otherwise, why not simply change “six-months” to “first”? After all, there are only two appointments.

  78. Sabine says:

    Your website has helped me a lot. However, I’m not sure, if I should use singular or plural in the following example:

    is an icon with 3 dots

    a 3-dot icon (singular like 5-foot fence)
    or a 3-dots icon, because the dots are plural?

    Hope you can help. Thanks a lot!

  79. Chrissy says:

    For ordinal number hyphenation for the following example, which would be correct?

    Nearly all American 10th graders plan to go to college.
    or
    Nearly all American 10th-graders plan to go to college.

  80. Susan says:

    Can you please help resolve an office debate? Is a hyphen needed when numbers are abbreviated? For example …

    The building is 1.35-million square-feet in size.

    Or, is it 1.35 million square-feet?

    Thank you!

    • Your example sentence does not contain a compound adjective in front of a noun. Therefore, no hyphens are required.
      The building is 1.35 million square feet in size.

  81. Ally says:

    Would you put a hyphen in between 24 and seconds?

  82. Svitlana says:

    Could you help me to choose the correct answer:
    The last one was a fisherman named Robert Jones, who at about 2-metres-tall/2 metre tall/2-metre-tall /2-metres tall would have found living in the house quite difficult.
    None of the variant seems to be correct.
    Thank you!

  83. Hello says:

    I think this is correct, but please could I get a second opinion?

    230-foot- (70-m-) high ledge

    as opposed to

    230-foot (70-m) -high ledge OR 230-foot- (70-m)-high ledge

    Basically I think the hyphen sticks with the preceding elements of the compound rather than the end – am I right?

    Thanks for your help in advance!

  84. Barb says:

    Ok. Sorry if I missed this one. We are having a debate about the following

    1-in-5 people
    vs.
    1 in 5 people

    It seems like your rule suggests that since the numbers are relative to the people noun, yes have the hyphens. But this looks/seems odd to me?
    Thanks!

  85. Ravindra says:

    Can I write “I’ll give it to you for two-fifty,” where the figure refers to two hundred and fifty dollars (or two dollars and fifty cents, for that matter)?

    • That may be used informally in spoken language where the individuals understand each other. However, we recommend writing out the dollar amounts in formal writing to avoid misunderstandings: two hundred fifty dollars, two dollars and fifty cents.

  86. Eliza says:

    Is “The fifteen-thousand-person town” correct? Or “The fifteen thousand-person town”? It’s my understanding that fifteen thousand doesn’t have a hyphen by itself. But as an adjective describing town, do we add one? (Sorry if you’ve already answered something like this in the comments. I read through a lot of them but didn’t see this scenario!) Thanks!

  87. Mark says:

    I am trying to apply the rules. Can you please tell me which are correct? The hyphenated examples look right, but I rarely see them hyphenated on the internet.

    She is the second-eldest child.
    vs.
    She is the second eldest child.

    Yellowstone is the eighth-largest national park in the United States.
    vs.
    Yellowstone is the eighth largest national park in the United States.

    She is a first-grade student. (She is in the first grade, not first-rate,)
    vs.
    She is a first grade student.

  88. bitseeker says:

    What about when hyphenating numeric ordinals that are part of a compound adjective? For example, “15th-level fighter,” “10th-year student,” or “22nd-year anniversary.” It seems that normal compound adjective rules apply (e.g., “fifth-degree master”), but I wasn’t able to find specific examples.

    • Compound adjectives with numeric ordinal numbers are hyphenated. However, the term “22nd-year anniversary” has an awkward feel. We would more commonly see “22nd anniversary” or “22-year anniversary.”

  89. Margie Jimenez says:

    What is the hyphen rule when writing 14 days or 14-days?

  90. Brooke says:

    Please help. The measurements will be abbreviated for the rest of the document and won’t need hyphens between the numbers and measurements, but what about the first sentence of the document that introduces the abbreviation?

    “The project area includes the 2,240-foot- (ft) (383-meter- [m]) long alignment.”

    • This appears to be a technical description that is being prepared for other professionals who would have basic knowledge of what you are describing. If this is the case, can your sentence be simplified without sacrificing meaning? One such simplification would be to simply not state the abbreviations in the first occurrence, just use them later, because everyone will know that ft means foot or feet and m means meter or meters. Also, is the word “long” necessary since feet and meters are measures of length? In such a case, you could write:
      The project area includes the 2,240-foot (683-meter) alignment. If you must include long, you might consider including it twice to reduce confusion: The project area includes the 2,240-foot–long (683-meter–long) alignment.

  91. Alice says:

    I’m editing a legal document, where the convention is to write out all (yes, all) numbers and then follow them with parenthetical numerals, i.e., “two (2) years.”

    How would this format work with hyphenated modifiers? For example, I’m trying to express “two-year period,” but the parenthetical has to be included as well. Does a hyphen get added to both the written out number and the numeral? Or should it not be used at all?

    Thanks!

  92. BD Cook says:

    In a policy handbook, this paragraph appears, “Each member may serve up to two consecutive three-year terms. If a vacancy occurs, the board will choose a replacement to fill the remaining term. Time spent as a replacement will not count toward the two term limit.” Or should I say ” . . . count toward the term limit” or “limits”? I don’t want the reader to confuse the length of a single term with the term limit.

    Your blog is fabulous! Maybe I am just being resistant to changing my initial language choice?

    • To avoid confusion, we recommend writing “two-term limit.” Since you are combining two or more words to form a compound adjective in front of a noun, a hyphen is used.

  93. Rita says:

    When someone says they have 8 out of 10 pain, should it be hyphenated or not? (ie: 8-out-of-10 pain)

    • It should be hyphenated since you’ve expressed the pain rating as a compound adjective, e.g., She has eight-out-of-ten pain. However, this would be considered an awkward phrasing. An alternative could be She rated her pain as eight out of ten. OR … eight on a scale of ten as the highest.

  94. Nancy Murphy says:

    Am I using the hyphen correctly with numbers as follows?

    We have two (2)- year terms left on the contract.

  95. Greg says:

    What about when you have an adjective and noun (basically forming a compound adjective) to describe a noun such as:

    Comes with a 12 page booklet. Is that correct or should it be 12-page booklet or is either correct?

  96. Shannon Jones says:

    Is it one-hundred-fifteen days left in the school year, one hundred-fifteen days left in the school year, or one hundred fifteen days left in the school year?

  97. Greg says:

    Should one use a comma between two compound adjectives or not inserting one is acceptable or are both acceptable as such:

    1) The CD comes with a 6-page accordion-style booklet.

    2) The CD comes with a 6-page, accordion-style booklet.

  98. Lonnie says:

    2 Questions. In a technical document would you write; “Allow 6″ (15 cm) clearance” or “Allow 6″ (15-cm) clearance?” Hyphen between the 15 and cm?
    2nd: “2” (5 cm) air gap” or “2” (5-cm) air gap?” Hyphen between the 5 and cm?

    • Our post Hyphenation with Numbers and Units of Measure says, “If an abbreviation or a symbol is used for the unit of measure, the quantity is always expressed by a numeral. Such usage is standard in mathematical, statistical, technical, or scientific text, where physical quantities and units of time are expressed in numerals, whether whole numbers or fractions, and almost always followed by an abbreviated form of the unit … Note that hyphens are never used between the numeral and the abbreviation or symbol, even when they are in adjectival form.” Therefore, we recommend the following:
      Allow 6″ (15 cm) clearance; 2” (5 cm) air gap
      OR
      Allow 6 in (15 cm) clearance; 2 in (5 cm) air gap
      “2” (5 cm) air gap

  99. Marcia Neely says:

    Which is correct:
    digging a six-foot-deep-hole or digging a six-foot deep hole?

  100. Amanda says:

    Would you need a hypen in the following example?
    The form would need to be returned in 30 calendar days.

  101. Lloyd Cunningham says:

    I am describing the dimensions of a boat and want to get it correct. I have written, “The boat looked like a small barge, a 30-foot-by-8-foot wooden box.” Do I need all those hyphens?

  102. Cee says:

    Please tell us the correct way to hyphenate in the following sentence:
    “The drive took eight and a half hours.”
    Thank you!

    • No hyphen is needed in your sentence. However, more formally you would write The drive took eight and one-half hours.
      And if you state your numbers as adjectives, you can have more hyphen fun: It was an eight-and-a-half-hour drive.

  103. Amber Krogh says:

    Would it be A nanorobot filled bandage came out of a sixteen-inch in diameter housing or A nanorobot filled bandage came out of a sixteen-inch-in-diameter housing?

  104. Catherine M Stefaniak says:

    How do I write 9 8 when referring to a baby’s size when the baby is 9 pounds and 8 ounces, but the person omitted the words pounds and ounces?

  105. Ber Lin says:

    What is appropriate?

    Our curriculum requires us to have 160-hour supervised training.

    Or

    Our curriculum requires us to have 160-hours supervised training.

  106. Jess S says:

    Wondering if there should be a hyphen between 30-day in my title that reads:
    Impact of Optimal Antibiotic Therapy for Pneumonia on 30 day Readmissions
    Thanks!

  107. Kate says:

    £150 worth of savings or £150-worth of savings?

  108. Rica T. Gonzaha says:

    Please help me about this one item reviewer for ept.
    It is observed that some new aspiring politicians usually make a ______ before running in congress with great hope of bringing changes in the system and progress in the country.

    a. two-hour important decision
    b. two-hours important decision
    c. two hour important decisions
    d. two hours important decisions

    Hopefully somebody will help me understand the rule in order for me to easily answer this type of question. Thank you in advance.

    • The article a in the sentence indicates that you need to use a singular noun (decision). When used as a compound adjective to describe a noun, the correct term is two-hour. Therefore, choice a is the best option, although we would rewrite the sentence as “It is observed that some new aspiring politicians usually make an important two-hour decision before running for Congress with great hope of bringing changes to the system and progress to the country.”

  109. Beth Sperber says:

    In the following sentence, should there be a hyphen after 30 AND 45, or just after 45?

    We give 30- to 45-minute classes.

    Thank you.

  110. Tom says:

    “This twenty-one-day process…”

    Is that correct?

    Many thanks.

  111. fernando says:

    Is “300-unit transistor radios” correct?

    • Unless you provide more information, the only context in which we can imagine this being correct would be something of the nature The store received a 300-unit shipment of transistor radios.

  112. Tom says:

    Will there be a hyphen between 6 metres?

  113. Stephen Babcock says:

    What about the standard “Void after 90 Days” that you see at the bottom of business checks? It’s never hyphenated. Should it be?

  114. Jane Doe says:

    I need some help dealing with measurements and distance. Is this correct:

    The project area was located approximately 100 feet (30.5 m) northeast of the building, within and south of an existing 28-foot (8.5 m) -diameter landscaped planter ring.

    and:

    The excavated area comprised a trench measuring approximately 10 feet (3 m) north–south by 6 feet (1.8 m) east–west, which was dug to a maximum of 2.8 feet (0.85 m) below surface within the circular concrete planter, adjoined by an approximately 20-foot-long (6.1 m), 2-foot-wide (0.61 m), 4-foot-deep (1.2 m) trench directing south from within the planter. Excavations impacted approximately 12.1 cubic yards (9.3 cubic meters), or 0.0023 acre, of soil.

    I’d appreciate it if you could let me know if my use of hyphens is correct, and if you see any other mistakes. Thanks!

    • What you have written is reasonable and your intent should be clearly understood by contractors and clients. This is an area where you can find different guidelines from different reference manuals. Three years ago we provided some guidance from a grammatical viewpoint when we interpreted the Chicago Manual of Style’s preferences in this matter in Hyphenation with Numbers and Units of Measure. Chicago would hyphenate numbers and units of measure as adjectives when the units are written out but omit hyphens with abbreviations. In that case, and being consistent in the use of units, you might have either:

      The project area was located approximately 100 feet (30.5 meters) northeast of the building, within and south of an existing 28-foot- (8.5-meter-) diameter landscaped planter ring.
      and:
      The excavated area comprised a trench measuring approximately 10 feet (3 meters) north–south by 6 feet (1.8 meters) east–west, which was dug to a maximum of 2.8 feet (0.85 meters) below surface within the circular concrete planter, adjoined by an approximately 20-foot-long (6.1 meters-), 2-foot-wide (0.61 meters-), 4-foot-deep (1.2 meters-) trench directing south from within the planter. Excavations impacted [removed?] approximately 12.1 cubic yards (9.3 cubic meters) of soil over an area of 0.0023 acre.
      or
      The project area was located approximately 100 ft (30.5 m) northeast of the building, within and south of an existing 28 ft (8.5 m) diameter landscaped planter ring.
      and:
      The excavated area comprised a trench measuring approximately 10 ft (3 m) north–south by 6 ft (1.8 m) east–west, which was dug to a maximum of 2.8 ft (0.85 m) below surface within the circular concrete planter, adjoined by an approximately 20 ft long (6.1 m), 2 ft wide (0.61 m), 4 ft deep (1.2 m) trench directing south from within the planter. Excavations impacted [removed?] approximately 12.1 cubic yards (9.3 cubic meters) of soil over an area of 0.0023 acre.

  115. Kristina says:

    I’m transcribing something. Do I need any hyphens for this?

    Those five to six days or six days were…

    Thank you.

  116. Melissa says:

    What would be the proper way to write the following?
    He paced back and forth in his forty-nine-square foot jail cell.
    Is there a way to abbreviate square foot? Does the number have to be spelled out since it’s less than 100?
    Thanks for any guidance!

    • Your options depend on which style guide you choose to follow. Our post Numbers: Words or Numerals? explains that America’s two most influential style and usage guides have different approaches. The Associated Press Stylebook recommends spelling out the numbers zero through nine and using numerals thereafter—until one million is reached. The Chicago Manual of Style recommends spelling out the numbers zero through one hundred and using figures thereafter—except for whole numbers used in combination with hundred, thousand, hundred thousand, million, billion, and beyond.

      You may want to avoid using abbreviations in formal writing; however, if you choose to use them, the abbreviation of square foot is sq. ft. In addition, our post Hyphenation with Numbers and Units of Measure notes that CMOS uses a period when abbreviating English units and does not use hyphens with them even in adjectival form. We recommend that you remain consistent in the style guidance that you choose. We side closer to guidance from The Chicago Manual of Style, which would recommend the following:

      He paced back and forth in his forty-nine-square-foot jail cell. OR
      He paced back and forth in his forty-nine sq. ft. jail cell.

  117. Nanna Bjerregaard says:

    Why is it called a 10-item test and not a 10-items test? Is there a rule for this?

    • GrammarBook.com says:

      A good guideline to remember and follow is to not pluralize number-noun adjectives that precede a singular, countable noun. In your example, “test” is a singular item that can be counted. The preceding number-noun adjective would therefore be singular (not pluralized). Another example is “the nine-year-old boy” (not “the nine-years-old boy”).

  118. Rachel says:

    What is the correct way to hyphenate the phrase “two to three year period”?

  119. Tyler says:

    Person is responding to a question.
    “Three hundred,” he said.
    Is it hypenated?

  120. Danny says:

    Would it be 1-month period or 1 month period?

    And would the answer be the same for higher numbers?

    Thanks

    • GrammarBook.com says:

      As explained in our Rules for Writing Numbers, America’s two most influential style and usage guides recommend spelling out the number one. Therefore, write “one-month period.” In regard to higher numbers, each style guide has different rules. Please refer to Writing Numbers to pick a style guide to follow and stay consistent.

  121. Layla says:

    If in my writing, I include a numerical reference when spelling out a numerical term, such as “one (1) payment,” what is the correct way to write “one-time payment” using the numerical reference in parentheses? I have been writing as “one- (1) time payment,” but I cannot find where I found that answer in the big world of the internet. All help appreciated.

    • GrammarBook.com says:

      Our recommendation is that it is generally not necessary to use both numerals and words for numbers. None of the style guides we consulted address this particular issue. If you are required to spell out numbers then follow with digits, our preference would be “one-time (1-time) payment.” Please see our post Writing Numbers as Both Numerals and Words for more information.

  122. Luis Felipe Salcedo says:

    I am having an issue with verbalizing something for some packaging I am working on, and it probably comes off as a silly question but I am unsure of the answer. The product I am working is advertising itself as a 1 to 5 gallon mixer. Is it proper to use hyphenation so it would be 1-to-5-gallon mixer? Or should I use an en dash so it’s 1—5-gallon mixer?

  123. Dr. L. Bower says:

    Which is more correct? quarter-inch wide or 1/4-inch wide in ficiton writing?

    • GrammarBook.com says:

      When writing fractions in fiction, spell them out: quarter-inch wide, half-inch wide, the quarter-inch-wide opening.

  124. samaneh vahedi says:

    How do I write “Something has happened in a 10- to 14-day period”?
    Is this correct?

    • GrammarBook.com says:

      The Chicago Manual of Style’s rule 7.88 says, “When the second part of a hyphenated expression is omitted, the hyphen is retained, followed by a space.” Whether you spell out the numbers or use numerals depends on which style guide you are following (see Writing Numbers).
      “Something has happened in a 10- to 14-day period.” OR
      “Something has happened in a ten- to fourteen-day period.”

  125. Erin says:

    This may be similar to a question previously asked, but if you have a range of numbers, would you use a hyphen between the numbers and the word “to”?

    For example:
    80 to 90-hour work week
    or
    80-to-90-hour work week

  126. Shawna says:

    I’m transcribing verbatim. Are these correct?
    2-by-12 board
    Affix the ladder to a 2-by-12 on the roof

    • GrammarBook.com says:

      We recommend the following:
      “two-by-twelve board” or “2-by-12 board”
      “Affix the ladder to a two-by-twelve on the roof.” or “Affix the ladder to a 2-by-12 on the roof.”

  127. Joanna says:

    I often see numerical fractions written with lots of hyphens….it just looks ugly.

    The one-and-a-half-inches cut from the length was enough.
    It took thirteen-and-three-quarters years to do it.
    The twenty-five-and-a-half-year-old man was twenty-five-and-a-half-years old.

    Is there a more elegant way to write these examples?

    • GrammarBook.com says:

      You do have an extra hyphen in a few of your examples:
      The one-and-a-half inches cut from the length was enough.
      The twenty-five-and-a-half-year-old man was twenty-five-and-a-half years old.

      Our Rule 5 of Writing Numbers says, “Mixed fractions are often expressed in figures unless they begin a sentence.” Therefore, you could write the following:
      The 1.5 inches cut from the length was enough.
      It took 13.75 years to do it. (Or simply “It took almost fourteen years to do it.”)
      We are not sure why you would need to repeat the man’s age twice in the same sentence.

  128. Rachel says:

    Are these correct?
    an intersection with four stop streets
    four-way intersection
    a container holding five litres
    five-litre container
    a car with four doors
    four-door car
    an interval of ten minutes
    ten-minute interval
    a note for fifty rand
    a fifty-rand note

  129. Petra says:

    Is “Get a 14 days free trial” correct?

  130. Brenda Freiheit says:

    Regarding this sentence: The first-floor, 2 1/2-ton condensing unit was manufactured in the year 2000.

    What I would do if I were writing this in a Word document would be to first hit enter after typing 1/2, so that it forms smaller-numbered, top-over-bottom fraction. Then, I’d delete the space between 2 and the fraction so that they were right up against each other. (Then, there would be no awkward-looking space between 2 and 1/2). Next, I’d put the hyphen between the fraction and ton. I can’t make it look like that on this app, but in Word or other document tools, it would look more acceptable that way.

  131. Carol says:

    I was wondering the correct way to hyphenate this sentence. I am editing a fellow scientist’s abstract for a talk later this month.

    This is what they have:

    The immobilization period lasted 3- or 7-days.

    I have never encountered hyphenation like this and am unsure if the above is correct or if it should be:

    The immobilization period lasted 3 or 7 days.

    OR

    The immobilization period lasted three or seven days.

    Thanks!

    • GrammarBook.com says:

      The sentence does not contain a compound adjective; therefore, no hyphens are necessary. In addition, our post Numbers: Words or Numerals? points out that America’s two most influential style and usage guides both recommend spelling out the numbers zero through nine.

      The immobilization period lasted three or seven days.

  132. Jinta says:

    Could you tell me which is correct?

    10 million person drill
    10 million-person drill

  133. Dawn Alberts says:

    If someone is referring to two trucks and says “Was the 50 ton ever out of service?” would that be hyphenated or not?

  134. Russ says:

    What if the noun is only implied? For example, in the sentence “What is the cost difference between a 6-inch fitting and an (8-inch or 8 inch),” what is the correct way to do it, since the 8 inch does not have a noun immediately following it? (There is an implied noun, and you are talking about an 8-inch fitting.)

  135. Shrub says:

    I am currently proofreading some text and had a question regarding hyphen usage. The sentence is “About 3 to 4 drops of the mixture is transferred.” Would it be 3-4 with a hyphen, an en-dash, or the word “to”?

    Thank you!

  136. Jamison says:

    Could you tell me if this would be correct in a novel?
    “… a fifteen-hundred to two-thousand-pound animal.”

    • GrammarBook.com says:

      The following are all acceptable:
      … a fifteen-hundred- to two-thousand-pound animal
      a 1,500- to 2,000-pound animal
      a 1,500–2,000-pound animal

  137. DeeDeeEn says:

    Is this rule compatible with numbers that are spelled out with hyphens; an example being “twenty-one-game disc”?

  138. Kris says:

    How would I hyphenate “a two tractor trailer accident?” Two-tractor-trailer accident or two tractor-trailer accident?

    • GrammarBook.com says:

      Since you have a compound adjective in front of the noun “accident,” we recommend writing “two-tractor-trailer accident.”

  139. Jill says:

    What is the correct way to use a hyphen in the below example?

    “Thirty (30) day period”

    My thought would be to type it:

    Thirty- (30) day period or Thirty (30)- day period, but this one has stumped me.

    Any help is appreciated.

    • GrammarBook.com says:

      Our recommendation is that it is generally not necessary to use both words and numerals for numbers. If you must write it that way, write “thirty (30)-day period.”

  140. Jessica says:

    I’m a copy editor and I love that this blog post and comments exist! I’m curious if it’s the most active, long-standing, set of blog replies on the Internet? Lol!

    Keep up the dedication!

  141. Courtney says:

    What is the proper use or non-use of hyphens in the two examples below?

    1. The wetland is 0.1 acre in size. OR The wetland is 0.1-acre in size.

    2. The wetland is 1/10 acre in size. OR The wetland is 1/10-acre in size.

    Thanks!

    • GrammarBook.com says:

      Your examples do not combine two or more words forming a compound adjective in front of a noun. Therefore, no hyphens are necessary.

  142. Dawn says:

    Are the hyphens correct in this sentence? I added them to a document I’m editing, but it looks like too many hyphens.

    “Off the top of my head, it’s a two- or three-times-a-week thing.”

  143. Martin says:

    Is a hyphen required when describing the caliber of a gun? “…they had to trade the antique .32 caliber pistol ” I have not seen a reference for this anywhere. Thanks!

    • GrammarBook.com says:

      Since the measurement forms a compound adjective in front of a noun, we recommend writing “.32-caliber pistol.”

  144. Lisa says:

    This is not a well-written sentence. How would you rewrite it? Would nine and one half months be hyphenated? Does months need to be plural?

    The College agrees to pay Appointee on the basis of a nine and one half months academic year a salary of $__________, subject to applicable payroll deductions.

    Thank you!

    • GrammarBook.com says:

      We would rewrite as follows:
      The College agrees to pay Appointee on the basis of a nine-and-one-half-month academic year a salary of $__________, subject to applicable payroll deductions.

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