# Description

An em is a measurement based upon the element's font size. Fractional values are allowed.

A length value is formed by an optional + or -, followed by a number, followed by the two-letter unit abbreviation. No spaces are allowed in the value.

1em is equal to font size of the parent (same as 100%).

# Examples

This example sets the paragraph font size to twice the current font's size.

    p {
      font-size:2em;
    }

# Browser Support

Firefox | IE | Chrome | Opera | Safari

# Miscellaneous Information

Defined In: | CSS2.1