Convert between px, em, rem and percent based on root size.
Free · Runs in your browser · Last updated
Set a root font size and convert any value between px, em, rem and percentage units instantly.
All processing for CSS Units happens locally inside your browser using JavaScript. Your input is never uploaded to a server, logged, or shared with third parties.
Yes. CSS Units is completely free for both personal and commercial projects. There are no usage limits, no sign-up, and no premium tier.
All processing happens locally in your browser using JavaScript. Your input is never uploaded to our servers, logged, or shared with any third party.
Once the page has loaded, the tool runs entirely client-side. You can disconnect from the internet and it will keep working in the same browser tab.
CSS Units works in all modern browsers, including the latest versions of Chrome, Firefox, Safari, Edge, Brave, and Opera, on desktop and mobile.
No. CSS Units runs in any modern web browser with no installation, browser extension, or account required.