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.

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.

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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

BCD tables only load in the browser

See also