width property CSS Reference

Definition and Usage

The width CSS property specifies the width of the content area of an element. The content area is inside the padding, border, and margin of the element.

The min-width and max-width properties override width.

  • Initial auto
  • Applies to all elements but non-replaced inline elements, table rows, and row groups
  • Inherited no
  • Percentages refer to the width of the containing block
  • Media visual
  • Computed Value the percentage or auto as specified or the absolute length
  • Animatable yes, as a length, percentage or calc(); when both values are lengths, they are interpolated as lengths; when both values are percentages, they are interpolated as percentages; otherwise, both values are converted into a calc() function that is the sum of a length and a percentage (each possibly zero), and these calc() functions have each half interpolated as real numbers.
  • Canonical order the length or percentage before the keyword, if both are present


Formal syntax: [<length> | <percentage>] && [border-box | content-box]? | available | min-content | max-content | fit-content | auto
width: 300px        /* <length> values */
width: 25em
width: 75%          /* <percentage> values */
width: border-box   /* Keyword values */
width: content-box
width: max-content
width: min-content
width: available
width: fit-content
width: auto
width: inherit


See <length> for possible units.
Specified as a <percentage> of containing block's width.
If present, the preceding <length> or <percentage> is applied to the element's border box.
If present, the preceding <length> or <percentage> is applied to the element's content box.
The browser will calculate and select a width for the specified element.
The intrinsic preferred width.
The intrinsic minimum width.
The containing block width minus horizontal margin, border and padding.
The larger of:
  • the intrinsic minimum width
  • the smaller of the intrinsic preferred width and the available width

Note: WebKit implements an earlier version of this value, under the name intrinsic, but as of June 2012, implements fit-content as well.


table { width: 100%; }
img   { width: 200px; }
form  { width: auto; }
p     { width: 40em; }
p {
  background: lightgreen;
  width: intrinsic;                     /* Safari/WebKit uses a non-standard name */
  width: -moz-max-content;      /* Firefox/Gecko */

Lorem ipsum dolor sit amet, consectetur adipisicing elit

p { background: lightblue;  max-width: -moz-min-content; }

Lorem ipsum dolor sit amet, consectetur adipisicing elit


Desktop browsers

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes) 1.0 (1.7 or earlier) 4 3.5 1.0 (85)
Animatability NA 16.0 (16.0) NA NA NA
max-content 22 -webkit 3.0 (1.9)-moz NA NA 2.0 (421) (intrinsic value)
min-content 22 -webkit 3.0 (1.9) -moz NA NA NA
available 22 -webkit 3.0 (1.9) -moz NA NA NA
fit-content 22 -webkit 3.0 (1.9) -moz NA NA NA
border-box and content-box Not supported Not supported Not supported Not supported Not supported

Mobile browsers

Feature Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support NA NA NA NA NA

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