Web platform features explorer

The rch CSS length unit is a font-relative length equal to the value of the ch unit on the root element. ch length is based on the width of the zero (0) character.

Status

Baseline Newly Available (since 2026-01-13)

This feature is expected to reach Baseline Widely Available status on: 2028-07-13

MDN documentation

Rch, in <length>

Specifications

CSS Values and Units Module Level 4 (#font-relative-lengths), from Cascading Style Sheets (CSS) Working Group (W3C).

Browser support

Chrome 111 Released on 2023-03-07
Chrome Android 111 Released on 2023-03-07
Edge 111 Released on 2023-03-13
Firefox 147 Released on 2026-01-13
Firefox for Android 147 Released on 2026-01-13
Safari 17.2 Released on 2023-12-11
Safari on iOS 17.2 Released on 2023-12-11

Usage (according to Chrome Platform Status)

~0.000% of page loads. More data at chromestatus.com.

Web Platform Tests (WPT)

View the latest WPT test results for this feature