inline-size

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2021.

* Some parts of this feature may have varying levels of support.

The inline-size CSS property defines the horizontal or vertical size of an element's block, depending on its writing mode. It corresponds to either the width or the height property, depending on the value of writing-mode.

If the writing mode is vertically oriented, the value of inline-size relates to the height of the element; otherwise, it relates to the width of the element. A related property is block-size, which defines the other dimension of the element.

Try it

Syntax

css
/* <length> values */
inline-size: 300px;
inline-size: 25em;
inline-size: anchor-size(width);
inline-size: anchor-size(--myAnchor inline);

/* <percentage> values */
inline-size: 75%;

/* Keyword values */
inline-size: max-content;
inline-size: min-content;
inline-size: fit-content;
inline-size: fit-content(20em);
inline-size: auto;

/* Global values */
inline-size: inherit;
inline-size: initial;
inline-size: revert;
inline-size: revert-layer;
inline-size: unset;

Values

The inline-size property takes the same values as the width and height properties.

Formal definition

Initial valueauto
Applies tosame as width and height
Inheritedno
Percentagesinline-size of containing block
Computed valuesame as width and height
Animation typea length, percentage or calc();

Formal syntax

inline-size = 
<'width'>

<width> =
auto |
<length-percentage [0,∞]> |
min-content |
max-content |
fit-content( <length-percentage [0,∞]> ) |
<calc-size()> |
<anchor-size()>

<length-percentage> =
<length> |
<percentage>

<calc-size()> =
calc-size( <calc-size-basis> , <calc-sum> )

<anchor-size()> =
anchor-size( [ <anchor-name> || <anchor-size> ]? , <length-percentage>? )

<calc-size-basis> =
<intrinsic-size-keyword> |
<calc-size()> |
any |
<calc-sum>

<calc-sum> =
<calc-product> [ [ '+' | '-' ] <calc-product> ]*

<anchor-name> =
<dashed-ident>

<anchor-size> =
width |
height |
block |
inline |
self-block |
self-inline

<calc-product> =
<calc-value> [ [ '*' | '/' ] <calc-value> ]*

<calc-value> =
<number> |
<dimension> |
<percentage> |
<calc-keyword> |
( <calc-sum> )

<calc-keyword> =
e |
pi |
infinity |
-infinity |
NaN

Examples

Setting inline size in pixels

HTML

html
<p class="exampleText">Example text</p>

CSS

css
.exampleText {
  writing-mode: vertical-rl;
  background-color: yellow;
  inline-size: 110px;
}

Result

Specifications

Specification
CSS Logical Properties and Values Level 1
# dimension-properties
CSS Box Sizing Module Level 4
# sizing-values

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
inline-size
anchor-size()
Experimental
fit-content
fit-content()
Experimental
max-content
min-content

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.
See implementation notes.
User must explicitly enable this feature.
Uses a non-standard name.
Requires a vendor prefix or different name for use.
Has more compatibility info.

See also