Web/CSS/dimension

The <dimension> CSS data type represents a <number> with a unit attached to it, for example 10px.

CSS uses dimensions to specify distances (<length>), durations (<time>), frequencies (<frequency>), resolutions (<resolution>), and other quantities.

Syntax

The syntax of <dimension> is a <number> immediately followed by a unit which is an identifier. Unit identifiers are case insensitive.

Examples

Valid dimensions

12px      12 pixels
1rem      1 rem
1.2pt     1.2 points
2200ms    2200 milliseconds
5s        5 seconds
200hz     200 Hertz
200Hz     200 Hertz (values are case insensitive)

Invalid dimensions

12 px       The unit must come immediately after the number.
12"px"      Units are identifiers and therefore unquoted.
3sec        The seconds unit is abbreviated "s" not "sec".

Specifications

Specification	Status	Comment
CSS Values and Units Module Level 4The definition of '<dimension>' in that specification.	Editor's Draft	Adds `cap`, `ic`, `lh`, `rlh`, `vi`, `vb`
CSS Values and Units Module Level 3The definition of '<dimension>' in that specification.	Candidate Recommendation	Adds `ch`, `rem`, `vw`, `vw`, `vmin`, `vmax`, `Q`
CSS Level 2 (Revision 1)The definition of '<dimension>' in that specification.	Recommendation	Defined under Numbers and Length
CSS Level 1The definition of '<dimension>' in that specification.	Recommendation	Initial definition under "length units"

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
<dimension>	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 5	Opera Full support 3.5	Safari Full support 1	WebView Android Full support ≤37	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0

Legend

Full support: Full support