coderef

calc-size()Limited availability

The calc-size() CSS function computes mathematical expressions that include height and width keyword values, for example calc-size(fit-content, size / 2). Not to be confused with the calc() CSS function, which cannot use keyword values.

Not yet supported in all major browsers — check the table and provide a fallback.

How to use ↓Compare browsers

Browser support

DesktopChrome
1–128Not supported
129+Supportedsince Sep 17, 2024
Current: 155
Edge
12–128Not supported
129+Supportedsince Sep 19, 2024
Current: 154
Firefox
✕Not supportedup to 157
Current: 157
Safari
✕Not supportedup to 27
Current: 27
MobileChrome Android
18–128Not supported
129+Supportedsince Sep 17, 2024
Current: 155
Firefox Android
✕Not supportedup to 157
Current: 157
Safari iOS
✕Not supportedup to 27
Current: 27

How to use

Not supported in Firefox, Safari, Firefox Android, Safari iOS. Use feature detection below and provide a fallback (or a polyfill) for those browsers.

Example

Full syntax and examples are on MDN: calc-size.

Feature detection

CSS · check before using
@supports (height: calc-size(auto, size)) {
  /* styles that use calc-size */
}

/* or in JavaScript */
if (CSS.supports("height", "calc-size(auto, size)")) {
  // use it
}

Documentation (MDN)

Specification