Hyphens vs. Dashes: When to Use a Hyphen, En Dash, or Em Dash

The Three Marks at a Glance

Before getting into details, here is a quick comparison:

The names come from typography: an en dash is roughly the width of the letter N, and an em dash is roughly the width of the letter M.

The Hyphen (-)

The hyphen is the shortest of the three marks and the most common. Its job is to join things together: two words into a compound, or a word split across two lines.

Compound Modifiers Before a Noun

When two or more words team up to modify a noun, and they appear before the noun, hyphenate them:

• a well-known author (but: the author is well known)
• a high-speed train (but: the train travels at high speed)
• a six-year-old child (but: the child is six years old)
• a thought-provoking question
• a last-minute decision

The key is position. When the compound modifier follows the noun, most style guides drop the hyphen. When it comes before, the hyphen clarifies that the two words work together as a unit.

Compound Nouns

Many compound nouns use hyphens, though usage varies by style guide and changes over time. Many compounds that once used hyphens have merged into one word as they became familiar:

• Still hyphenated: mother-in-law, runner-up, editor-in-chief, check-in
• Now one word: email, website, online, smartphone
• Two separate words: coffee shop, real estate, ice cream

When in doubt, check a current dictionary. Usage shifts, and dictionaries track it.

Prefixes

Most prefixes attach directly to the word without a hyphen: preorder, undo, rewrite, nonprofit. Hyphens are used with prefixes in these cases:

• The base word is a proper noun: pre-Columbian, anti-American, non-English
• The prefix ends with the same vowel that starts the base word and a hyphen aids readability: re-enter, co-opt, de-emphasize
• The word would be ambiguous without a hyphen: re-cover (cover again) vs. recover (get better); re-sign (sign again) vs. resign (quit)

Numbers and Fractions

Hyphenate spelled-out numbers from twenty-one through ninety-nine. Also hyphenate fractions when they are used as modifiers:

• forty-seven, sixty-three, ninety-nine
• a two-thirds majority (modifier before noun)
• Two thirds of the votes were counted. (no hyphen when used as a noun)

Line-Break Division

In print typesetting, hyphens divide words that are too long to fit on one line. This is done at a syllable boundary. In most digital writing, word processors and browsers handle this automatically, so you rarely need to insert hyphens for this purpose.

Do Not Use a Hyphen When

• An adverb ending in -ly is part of the compound: a clearly written report, a highly regarded scientist (no hyphen needed because the adverb can only modify the adjective, not the noun)
• The compound modifier comes after the noun: The decision was last minute.
• Using very or more: a more reliable method, a very cold day

The En Dash (–)

The en dash does a different job from the hyphen. It indicates a range or connection between two things that are related but separate, especially things of equal weight.

Ranges of Numbers, Dates, and Times

This is the most common use of the en dash:

• Pages 14–27
• The 2010–2015 fiscal period
• Office hours: 9:00 a.m.–5:00 p.m.
• The score was 3–1.

In running text, use from...to or between...and instead of an en dash: from 2010 to 2015, between 9 and 5. Reserve the en dash for tabular data, captions, or parenthetical references.

Connections Between Places, Names, or Concepts

When two equal elements are linked, the en dash shows that relationship:

• The New York–London flight (connecting two places of equal status)
• The Democrat–Republican divide
• A cost–benefit analysis
• The parent–child relationship

Notice that if you used a hyphen here, readers might think you meant a compound modifier describing a noun. A New York-London flight could be read as a flight that is New York-London (hyphenated compound adjective) rather than a flight connecting the two cities.

Compound Adjectives with Multi-Word Elements

When one part of a compound modifier is itself multiple words, use an en dash instead of a hyphen:

• a post–World War II economy
• a pre–Civil War era
• Nobel Prize–winning research

How to Type an En Dash

• Windows: Alt + 0150 on the numeric keypad
• Mac: Option + hyphen
• HTML entity: – or –
• Many word processors auto-convert a hyphen flanked by spaces into an en dash

The Em Dash (—)

The em dash is the most expressive punctuation mark in English. It creates a strong pause or break in a sentence, more forceful than a comma or parenthesis and less final than a period.

Parenthetical Remarks

Two em dashes can set off a parenthetical phrase, similar to parentheses but with more emphasis:

• The committee—which had not met in six months—reached a decision within the hour.
• Her third novel—a mystery set in Prague—became a bestseller.

Use em dashes when the parenthetical is closely related to the surrounding sentence and you want to emphasize it. Use actual parentheses when the aside is supplementary or tangential.

Attribution After a Quotation or Summary

A single em dash introduces attribution at the end of a standalone quotation:

• "The only way out is through." —Robert Frost
• "In the middle of difficulty lies opportunity." —Albert Einstein

Abrupt Interruption or Shift

In dialogue or narrative, an em dash marks a sentence that breaks off suddenly:

• "I was going to say—but never mind."
• She opened the door and found—nothing. The room was empty.

Summary After a List

An em dash can introduce a summary clause that follows a series of listed items:

• Courage, creativity, and persistence—these are the traits that define great entrepreneurs.
• A strong hook, clear structure, and a memorable conclusion—every good essay needs all three.

Em Dash Spacing

American style (Chicago, AP, most American publishers) uses the em dash with no spaces on either side: The answer—when it finally came—surprised everyone.

British style and some Canadian publications use spaces around the en dash instead of the em dash: The answer – when it finally came – surprised everyone.

Pick one style and use it consistently throughout a document.

Em Dash Overuse

The em dash is powerful precisely because it is distinctive. Overuse dilutes that effect and can make writing feel choppy or breathless. Limit yourself to two or three em dashes per article or essay. If you find yourself using more, replace some with commas, parentheses, or restructured sentences. See the section on how to use commas for alternatives.

How to Type an Em Dash

• Windows: Alt + 0151 on the numeric keypad
• Mac: Option + Shift + hyphen
• HTML entity: — or —
• Word processors often auto-convert two hyphens (--) into an em dash

Common Errors to Avoid

Using Two Hyphens Instead of an Em Dash

Typed text often substitutes two hyphens (--) for an em dash. This is a holdover from typewriter days when there was no dash key. Modern writing should use the actual em dash character.

Using a Hyphen for a Range

Writing pages 14-27 with a hyphen instead of an en dash (pages 14–27) is a common shortcut that slips through in informal or quickly edited text. In published work, always use the en dash for ranges.

Hyphenating Compound Adjectives That Follow the Noun

A well-known fact needs the hyphen. The fact is well known does not. Many writers hyphenate regardless of position, which is technically incorrect in most style guides.

Confusing En and Em Dashes

These two are easy to mix up visually, especially on screen. If you are uncertain which you have typed, check the character count: an en dash is one character (–) and so is an em dash (—), but they are different Unicode characters. In most word processors you can check via Insert > Symbol or by looking at the character code.

Quick Reference: Which Mark to Use

Related Punctuation: The Apostrophe

Like hyphens and dashes, apostrophes are small marks with specific jobs. If you are reviewing your punctuation, the apostrophe is worth checking alongside hyphen and dash usage. Both marks are frequently misused in ways that change meaning or mark a writer as inattentive.

Frequently Asked Questions

Is it ever correct to use two hyphens instead of an em dash?

In informal email, text messages, or quick drafts, two hyphens are universally understood as a substitute for an em dash. In any edited or published document, use the actual em dash character. Most word processors will auto-correct two hyphens to an em dash if that setting is enabled.

Should there be spaces around an em dash?

American English (Chicago Manual of Style, AP Stylebook) uses no spaces: word—word. British and Australian English often use spaces around an en dash instead of an em dash: word – word. Either approach is acceptable as long as you are consistent within a document.

When do I drop the hyphen from a compound modifier?

Drop it when the compound modifier follows the verb rather than preceding the noun: a well-organized team becomes the team was well organized. Also drop it when an adverb ending in -ly is part of the compound: a perfectly timed entrance.

What is a suspended hyphen?

A suspended hyphen (also called a hanging hyphen) allows you to apply a single base word to multiple prefixes: first- and second-year students rather than first-year and second-year students. The hyphens after first and second signal that both prefixes attach to the same base word, year.

Does the Oxford comma apply to hyphens or dashes?

No, the Oxford comma concerns commas in a series. It has no relationship to hyphen or dash usage. The two conventions are independent of each other.

How do hyphens and dashes appear in URLs?

Web URLs use hyphens as word separators because spaces and special characters are not allowed. The hyphens in URLs are technical, not grammatical. They do not follow any of the rules in this guide. For SEO purposes, hyphens between words in a URL are the standard across all major search engines.