Curious about using dashes in your writing?

Using Dashes: En Dash, Em Dash, 2 Em Dash, or 3 Em Dash?

Courtesy of Scribendi-- Everything you’ve ever wanted to know about dashes!

Don't dash to use dashes! Dashes can be

complicated, so read these helpful tips

before using them in your writing.

If you’re confused about the various types of dashes and when to use them, you’re not alone. Figuring out whether to use an en dash, em dash, 2 em dashes, or even (gasp!) 3 em dashes can be confusing.

En dash 

In ranges

The en dash (–) gets its name because it’s the same width as the letter N. It is generally used in place of “to” for connecting numbers in ranges, although it can also connect words (in which case, it means “through”). For example,
David Foster Wallace (1962–2008)
May–October
25–45°C
The Packers won 21–14.
Note that an en dash should not be used for negative numbers, and that there should be no spaces before or after it. It should also not be used when the number or word is preceded by from or between (from…to, or between…and). So,
The park is open from May to October.                       The temperature is 32–45°F.
Or…                                                                                        Or…
The park is open May–October.                                  The temperature is between 32 and 45°F.              
But not…                                                                                But not…
The park is open from May–October.                          The temperature is between 32–45°F.

Instead of a hyphen

The en dash can be used when joining compound modifiers. For example,
New York–Tel Aviv connection
Mother-of-the-bride–approved dresses
Post–October Revolution politics

Creating an en dash

Creating an en dash can be done by either:

• [ctrl] and the minus sign on the numpad or
• [alt] 0150 (on the numpad)

Em dash

The em dash (— or -- [on an old-fashioned typewriter]) is the most commonly used type of dash and is often simply referred to as a dash. It gets its name—no big surprise here—because it’s the width of an M. The em dash is used primarily in informal writing in place of a comma, colon, semicolon, or parentheses to provide emphasis.

Set off parenthetical elements/explain

When I was driving—well, asleep at the wheel—I got into an accident.
The em dash in this example could be substituted with a parenthesis, but not a comma because commas cannot be used to set off parenthetical expressions when there is internal punctuation (such as commas inside the expressions), as can be seen in the following example.
When I was driving, well, asleep at the wheel, we got into an accident.

Sudden turn in thought/break in dialogue

“Mary, How could—Why would you do such a thing?”
“Can I finish my—,” the child pleaded.
“No! Get over here right now,” his mother shouted.

Unknown values in a table

An em dash can be used in place of an unknown value in a table.

Time (h)	Volume (mL)
24	12
48	8
72	—

 Creating an em dash

Creating an em dash can be done by either:

• [ctrl] [alt] and the minus sign on the numbers pad or
• [alt] 0151 (on the numpad)

2 em dash

The 2 em dash can be used to indicate missing letters in a word, either because material is missing or illegible, or to conceal a name. For example,
Mr. H—— and Mr. S—— entered into a legal agreement.

3 em dashes

These are used in bibliographies when the author’s name is repeated.
———. Adventures in Fancy. New York: Labadie & Sons. 2010.