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-sizeCSS 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: #ffffff; }

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 value	`auto`
Applies to	same as `width` and `height`
Inherited	no
Percentages	inline-size of containing block
Computed value	same as `width` and `height`
Animation type	a 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