There are 2 definitions of em in English:


Line breaks: em


  • 1A unit for measuring the width of printed matter, equal to the height of the type size being used.
    More example sentences
    • From there, sizing descendant elements with ems (a relative unit of measurement) becomes much more logical: 1em is 10 px, 1.6em is 16 px, .9em is 9px, and so forth.
    • Sterne was almost compulsively attentive to page layout and typography, going so far as to specify the length of each dash in printer's ems.
    • It doesn't matter which unit you use - zero horseshoes is the same as zero pixels, ems, or percentages.
  • 1.1A unit of measurement equal to twelve points.
    More example sentences
    • So, a font size of 1.25 ems will be displayed as 1.25 pixels.
    • This reduced the text to an unreadable level when the CSS specified sizes in ems, but only reduced it slightly when specified as percentages.


late 18th century: the letter M represented as a word, since it is approximately this width.

More definitions of em

Definition of em in:

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day astrogation
Pronunciation: ˌastrə(ʊ)ˈgeɪʃ(ə)n
(in science fiction) navigation in outer space

There are 2 definitions of em in English:


Syllabification: EM

Entry from US English dictionary


  • 1Electromagnetic.
  • 1.1Engineer of Mines.
  • 1.2Enlisted man (men).

More definitions of em

Definition of EM in: