Pixels to REM converter

Convert between px and rem for responsive layouts.

Converts live as you type. Nothing is uploaded.

How to use this tool

Set your root font size, which is 16 pixels in most browsers by default. Type into either the pixels or rem box and the other updates instantly.

The formula

rem = pixels / root font size pixels = rem x root font size

A real example

You want a heading that is 24 pixels but defined in rem so it scales with the user's settings. At a 16 pixel root, that is 1.5rem. Using rem means a reader who increases their browser font size sees your layout grow with them.

Common questions

Why use rem instead of px?

Rem respects the user's font-size preference, which improves accessibility, while pixels stay fixed regardless of that setting.