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

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

Try it

max-inline-size: 150px;
writing-mode: horizontal-tb;

max-inline-size: 150px;
writing-mode: vertical-rl;

max-inline-size: 20px;
writing-mode: horizontal-tb;

max-inline-size: 75%;
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 max-inline-size.
  </div>
</section>

#example-element {
  display: flex;
  flex-direction: column;
  background-color: #5b6dcd;
  height: 80%;
  justify-content: center;
  color: white;
}

Syntax

/* <length> values */
max-inline-size: 300px;
max-inline-size: 25em;
max-inline-size: anchor-size(width);
max-inline-size: anchor-size(--my-anchor self-block, 200px);

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

/* Keyword values */
max-inline-size: none;
max-inline-size: max-content;
max-inline-size: min-content;
max-inline-size: fit-content;
max-inline-size: fit-content(20em);

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

Values

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

Formal definition

Formal syntax

max-inline-size = 
  none             |
  <box-size>       |
  <anchor-size()>  

<box-size> = 
  <length-percentage [0,∞]>                 |
  stretch                                   |
  contain                                   |
  min-content                               |
  max-content                               |
  fit-content                               |
  stretch( <length-percentage [0,∞]> )      |
  fit-content( <length-percentage [0,∞]> )  |
  <calc-size()>                             

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

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

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

<anchor-name> = 
  <dashed-ident>  

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

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

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

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

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

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

Examples

Setting maximum inline size in pixels

HTML

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

CSS

.exampleText {
  writing-mode: vertical-rl;
  background-color: yellow;
  block-size: 100%;
  max-inline-size: 200px;
}

Result

Specifications

Browser compatibility

See also

• The mapped physical properties: max-width and max-height
• writing-mode