CSS Units

最終更新：2026-09-13

CSS units express lengths, angles, times and other quantities. They split into absolute, relative and viewport-based families.

Absolute Length

CSS Units	Description
`px`	Pixels: 1px is one device pixel (CSS reference pixel).
`pt`	Points: 1pt = 1/72 of an inch.
`in`	Inches: 1in = 96px = 2.54cm.
`cm`	Centimeters.
`mm`	Millimeters.

CSS Units	Description
`em`	Relative to the font-size of the element.
`rem`	Relative to the font-size of the root element.
`ex`	Relative to the x-height of the element's font.
`ch`	Relative to the width of the '0' (zero) glyph.

CSS Units	Description
`vw`	1% of the viewport width.
`vh`	1% of the viewport height.
`vmin`	1% of the smaller viewport dimension.
`vmax`	1% of the larger viewport dimension.

CSS Units	Description
`%`	Relative to another value (parent size, property context).

CSS Units	Description
`s`	Seconds.
`ms`	Milliseconds (1000ms = 1s).

CSS Units	Description
`initial`	Sets a property to its initial (default) value.
`inherit`	Takes the computed value from the parent.
`unset`	Acts as inherit for inherited props, initial otherwise.

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