inline-size CSS property

Baseline
Widely available
*

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

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

The inline-size CSS property defines the size of an element's block along the inline axis. If the writing-mode is horizontal, it corresponds to the width; if the writing mode is vertical, it corresponds to the height. A related property is block-size, which defines the other dimension of the element.

Try it

inline-size: 150px;
writing-mode: horizontal-tb;
inline-size: 150px;
writing-mode: vertical-rl;
inline-size: auto;
writing-mode: horizontal-tb;
inline-size: auto;
writing-mode: vertical-lr;
<section class="default-example" id="default-example">
  <div class="transition-all" id="example-element">
    This is a box where you can change the inline-size.
  </div>
</section>
#example-element {
  display: flex;
  flex-direction: column;
  background-color: #5b6dcd;
  height: 80%;
  justify-content: center;
  color: white;
}

Syntax

css
/* <length> values */
inline-size: 300px;
inline-size: 25em;
inline-size: anchor-size(width);
inline-size: anchor-size(--my-anchor 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 = 
auto |
<box-size>

<box-size> =
<length-percentage> |
stretch |
contain |
min-content |
max-content |
fit-content |
fit-content( ) |
calc-size( )

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

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 Module Level 1
# dimension-properties
CSS Box Sizing Module Level 3
# sizing-values

Browser compatibility

See also