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) 

<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

See also

Last modified: Aug 12, 2021, by MDN contributors