The use of dashes is inconsistent in lots of writing – regardless of how ‘professional’ the writers are. The hyphen, em dash and en dash crop up all the time while you’re using Microsoft Word, but most of us don’t know why and we use the different dashes inconsistently. I had to figure this out.

What do they look like?

It’s interesting that the ways to spell the names of the dashes are not agreed on. But, whether someone write en dash, endash, n-dash or ndash, they are always spoken the same and refer to the same thing.

Let’s look at those dashes with some text:

Some web browsers display en dashes automatically. So, in the example above, on some devices it can be hard to see a differences. But there are differences. Let’s make that more clear.

The en dash is about as wide as an uppercase N; the em dash is as wide as an M.
(This image was made with PowerPoint and Photoshop; the relative sizes of the dashes look right but, here, the en dash and em dash don’t exactly match the width of the upper-case N and M.)

When should I use a hyphen, endash or emdash?

Hyphen

• Indicates breaks within words that wrap at the end of a line
• Connects compounded words like “mass-produced” (Closed compound words like counterintuitive have no hyphen in modern English, except for uncommon combinations that are confusing or ambiguous without a hyphen.)
• Connects grouped numbers, like a phone number 555-860-5086
• The hyphen does not indicate a range of numbers, like a date range, which is the job of an en dash

En dash

• Joins numbers in a range, such as “1993–99” or “1200–1400 B.C.” or “pages 32–37” or open-ended ranges, like “1934–”
• Joins words that describe a range, like “July–October 2010”

Em dash

• Works better than commas to set apart a unique idea from the main clause of a sentence:

“Sometimes writing for money—rather than for art or pleasure—is really quite enjoyable.”