Skip to content
POSTCSS / UNIT SYSTEMS / 2026
.card{padding:24px;→1.5rem;}
CSS unit conversion that stays close to your PostCSS pipeline. Choose a focused plugin for a familiar API, or compose rules when your design system needs more room.
Find the right conversion
| You start with | You need | Start here |
|---|---|---|
rem | px or rpx | postcss-rem-to-responsive-pixel |
rem | vw, vh or another viewport unit | postcss-rem-to-viewport |
px | platform-aware rpx, rem, vw or px | postcss-pxtrans |
| mixed units | px with a custom unit map | postcss-units-to-px |
| mixed units | composable rules and presets | postcss-rule-unit-converter |
A small toolkit with a shared core
Every plugin is published independently and tested against PostCSS 8. Shared matching, rounding, exclusion and declaration helpers live in postcss-plugin-shared, so the focused packages can keep their APIs small.
Copyable examplesInstall commands and PostCSS configs you can paste into a project.
Before / after outputSee exactly how a declaration changes before you tune options.
Migration pathsMove from a focused package to the rule engine with side-by-side recipes.