The em dash, known in French as the tiret cadratin, is the longest of the dashes: “—”. Its name comes from its width, which corresponds to one em, that is, the width of the letter “M” or the body size of the font. It is distinct from the hyphen (-) and the en dash (–), both of which are shorter.
Where to see it
The em dash is found above all in English texts, where it sets off a parenthetical phrase or marks a break in the sentence. In French, it appears mainly at the start of lines of dialogue, or to introduce the items of a list.
Why this detail matters
Choosing the right dash and using it well affects the legibility and quality of a text:
- Its length and weight vary from one font to another, making it a telling sign of the care that has gone into a typeface’s design;
- French convention surrounds it with spaces, whereas English usually sets it tight against the words: the rule depends on the language of the text;
- Used too often, it makes reading heavy and can give an artificial tone; commas, parentheses or colons are often a better fit.
Related term
The en dash (–), called tiret demi-cadratin in French, is shorter than the em dash; in French it is most often used for parenthetical phrases and ranges, such as “2020–2026”.
Anatomy glossary
Ascender, Descender, Sidebearing, Joint, Axis, Bar, Beak, Bowl, Loop, Set width, Counter, Serif, Stem, Leg, Minim, Baseline, Eye, Belly, Foot, Point, Tail, Cross stroke, Terminal; X-height, X-height, Cap height, Body; Mean line, Ear, Spur, Ball terminal, Ligature, Apex, Vertex, Arm, Shoulder, Spine, Em dash, Thick stroke, Hairline, Bracket, Bounding box