Grammar Dashes vs. Hyphens |
The Blue Book of Grammar and Punctuation

Dashes vs. Hyphens

Sometimes it can be easy to confuse dashes with hyphens when writing or editing content. For example, you might see text such as 9am-5pm in one reference and 9am–5pm in another. Which is correct? The two different marks do not interfere with our understanding of the intended information; however, one mark is more precise than the other. Being able to distinguish dashes and hyphens adds another useful instrument to our communicator’s toolbox.


In formal writing, a hyphen’s main function is to join two or more separate words, as in a compound noun, a compound modifier, or certain terms with a prefix.

Hyphen in a compound noun: well-being, dry-cleaning, hocus-pocus, merry-go-round
Hyphen in a compound modifier: blue-green sky, much-heralded activist, true-to-form performance
Hyphen with a prefix: self-help, self-motivated, ex-Marine, mid-Atlantic

Other uses of hyphens include:

clarifying words that are otherwise identical: re-cover (as opposed to recover), re-form (as opposed to reform).
separating vowels that might complicate reading if left together: pre-empt, anti-inflation, pro-ownership.
spelling out numbers and fractions: twenty-five, seventy-eight, one-third.
separating non-inclusive numbers: 888-555-2374, edict 74-54-293.


In formal writing, dashes have two common forms: the em dash and the en dash.

The em dash primarily replaces commas, semicolons, colons, ellipses, and parentheses to indicate added emphasis, an interruption, or an abrupt change of thought.

You are the friend—the only friend—who offered to help me. (The em dash replaces commas.)
I pay the bills—they have the fun. (The em dash replaces a semicolon.)
Throughout the game, he was able to rely on his three core pitches—fastball, slider, change-up. (The em dash replaces a colon.)
I was considering something more along the lines of—oh, forget it. Your idea is fine. (The em dash replaces ellipses.)
Helena wants her diet to contain more fruit—e.g., apples, oranges, and strawberries. (The em dash replaces parentheses.)

The en dash is shorter than an em dash but longer than a hyphen. It has two main functions. One is to connect continuing, inclusive numbers.

pages 11–23
fiscal year 2020–21

The other function is to punctuate compound modifiers that include an open compound or two or more hyphenated compounds.

ice cream–flavored chewing gum (not ice-cream-flavored)
Canada–New Zealand flight (not Canada-New-Zealand)
pseudo-scientific–pseudo-psychiatric self-help theory (not pseudo-scientific-pseudo-psychiatric)


Pop Quiz

Choose the correct mark—a hyphen, an em dash, or an en dash—for each of the following sentences.

1. Alphonso attended the University of Illinois 1981[- / – / —]1985.

2. I never imagined I’d like music so much[- / – / —]until I bought and played a Fender Strat, that is.

3. My brother lives near the California[- / – / —]Oregon border.

4. The new healthcare initiative would cover pre[- / – / —]existing conditions.

5. Scott is stalling on negotiations[- / – / —]his modus operandi[- / – / —]because he wants us to flinch on pricing first.


Pop Quiz Answers

1. Alphonso attended the University of Illinois 1981–1985. (en dash)

2. I never imagined I’d like music so much—until I bought and played a Fender Strat, that is. (em dash)

3. My brother lives near the California-Oregon border. (hyphen)

4. The new healthcare initiative would cover pre-existing conditions. (hyphen)

5. Scott is stalling on negotiations—his modus operandi—because he wants us to flinch on pricing first. (em dashes)

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.

13 responses to “Dashes vs. Hyphens”

  1. Lars says:

    In your section on dashes, you say that an em dash is the length of an “m”;
    in fact, it is the length of an “M.”

    • says:

      The length of en and em dashes is no longer as clear cut as it may have been in the past. The following is from Wikipedia, but there are several other sources with similar information:

      The en dash, n dash, n-rule, or “nut” (–) is traditionally half the width of an em dash. In modern fonts, the length of the en dash is not standardized, and the en dash is often more than half the width of the em dash. The widths of en and em dashes have also been specified as being equal to those of the upper-case letters N and M respectively, and at other times to the widths of the lower-case letters.

  2. Mary H. says:

    I found your info on dashes, specifically en dashes and em dashes.

    For both en and em you suggested: type in the word, hold down the ALT key while typing 0150 (for en) and 0151 (for em) on the numerical pad on the right side of the keyboard. On my keyboard, this didn’t work for either. However, you also suggested, as an alternative (for em), typing the first word, hitting the hyphen key twice and then typing the second word. This did work. But you didn’t provide a similar move for the en dash. Since this would seem to be the way for me to go, would you mind letting me have the en solution.

    Many thanks (and, by the way, your grammar columns are invaluable).

    • says:

      After consideration, we have decided to discontinue differentiating between the en and em dashes. Most word processing programs seem to easily handle hyphens and em dashes. While magazines and books still use en dashes, they are handled differently by different publishers. It’s a minefield and we’d rather leave this matter to the printers. In the eleventh edition of The Blue Book of Grammar and Punctuation (February 2014), and on our website, we are letting the hyphen do the work of the en dash, and the em dash is simply now the dash or long dash.

      We use PCs, and the ALT0150 and 0151 methods work for us. Some Mac users have reported this does not work for them. Do you use a Mac? Unfortunately, we do not have an alternative en dash solution for you.

  3. Peter Anderegg says:

    I think this information may not be accurate. In the category of “dashes” most style manuals, including APA and the Chicago Style Guide talk about 3 glyphs:
    Hyphen: This is the shortest dash and is used for compound words and non-sequential numbers, like a phone number e.g. 555-1212
    En Dash: Basically the width of the letter “n” and used for series, e.g. “The years 1929–1941 were brutal”, not “The years 1929-1941 were brutal” (sic)
    Em Dash: Basically the width of the letter “m” and used to show a change of thought: We were in Kansas—Missouri was just across the border. (note: this text box does not support a true “em” dash here represented by 3 hyphens. Most contemporary fonts include a glyph for the “em” dash, available through Uni Code as U+2014)

    • says:

      Some use an en dash where others use a hyphen. In our view, the en dash is a visual aid more than anything else, and everyone uses it a little bit differently.

  4. Nathan H. says:

    Greetings, Grammar Book editors.

    I was just about to share one of your pages with a colleague, but then I noticed a bit of text that contradicts a rule about hyphens and dashes.

    Question: In your article on Hyphens, it is stated that a hyphen is the correct character to indicate a range between numerals; however, this is incorrect. An en dash should be used for a range between numerals (where the numerals are not the birth and death dates of a human). Is this intentional guidance or is this an error?

    Incorrect: 300—325 people
    Incorrect: 300 – 325 people
    Correct: 300-325 people

    Correct: 300–325 people (En dash, not a hyphen. I believe that this is supported by historical usage as well as The Chicago Manual of Style.)

    Suggestion: Your site clearly displays the beginning of each section with the orange headings, as in “Hyphens Between Words”. Perhaps a section on “Hyphens Between Numerals” would be a good way to highlight the concept of hyphens vs. dashes.

    • says:

      If you go to the latest updates to the Blue Book of Grammar and Punctuation on our website (Hyphens, Rule 6), you will find that we have included en dashes in the discussion. But it is far too strong to use words like “incorrect” and “error” for spans that are stated with hyphens. En dash vs. hyphen is a matter of style and preference. The venerable Associated Press Stylebook does not even acknowledge the en dash, for this or any other purpose.

  5. Liberty C. says:

    Regarding Rule 3, if the writer prefers not to, is it okay? What’s the rule?

    • says:

      This is a gray area; there is no hard-and-fast rule. Most authorities, including The Chicago Manual of Style, recommend no spaces, while The Associated Press Stylebook prefers spaces. Our recommendation, as shown in Rules 1 and 2 of Dashes, is no spaces around dashes.

  6. Kristina B. says:

    I was just on your website, looking at the Hyphens section. Your first example for hyphens has an example using a range of number of people:

    Incorrect: 300—325 people
    Incorrect: 300 – 325 people
    Correct: 300-325 people

    When used for number ranges, an en dash should be used rather than a hyphen. None of the above is actually correct. See below for correct usage. I recommend changing your example.

    Correct: Incorrect: 300-325 people
    Correct: 300–325 people

    • says:

      Standard grammar and punctuation references for expressing number ranges offer no universal agreement. The Associated Press Stylebook, for example, uses a hyphen for inclusive number ranges. The Chicago Manual of Style, on the other hand, would use the en dash for them.

      Following AP‘s established lead, we used a hyphen in the “Correct” example in our introduction to rules for using hyphens. We could have used an en dash in the example and been equally correct, particularly among those who refer to CMOS more often. We continue to acknowledge both style books.

      Of equal note, in Rule 6 of the Hyphens Between Words section just below the introductory portion you referred to, we include this statement: “Most publishers use the slightly longer en dash instead of a hyphen in this situation.”

      In sum, you would be correct using either punctuation depending on the style choice you make. The key is to remain consistent with it.

  7. leftylimbo says:

    Thanks so much for sharing this information. I’d actually come here to research the correct use of hyphens, but it’s always good to brush up on the use of en- and em-dashes. I’d learned the differences years ago when I worked for a Behavioral Research Center, where writing research grant proposals were a constant and very enduring task. Basically, there was zero tolerance for grammatical errors, so everyone on board had a CMOS on their desktop.

    BTW, if anyone needs to know how to create en- and em-dashes on Macs, it’s very simple.

    Just type OPTION+hyphen for an en-dash, and OPTION+SHIFT+hyphen for an em-dash.

    Thanks again for your help!

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