712Tools

PX to REM Converter

Convert between pixels and REM units for responsive CSS

🔒 100% in-browser🆓 Free forever⚡ No sign-up
Common sizes
PixelsREMSample
12px0.75remAa
14px0.875remAa
16px1remAa
18px1.125remAa
20px1.25remAa
24px1.5remAa
32px2remAa
40px2.5remAa
48px3remAa
64px4remAa

REM is relative to the root <html> font size — usually 16px by default. Using REM instead of PX means your layout scales when users change their browser text size.

How it works

  1. 1
    Set the base

    The default root font size is 16px — the browser default. Change it if your CSS overrides it.

  2. 2
    Type in either field

    Enter pixels or REM; the other updates instantly.

  3. 3
    Reference the table

    Common design-system sizes are pre-converted, with a visual preview of each font size.

About PX to REM Converter

Free online PX to REM converter. Type a pixel value to get the REM equivalent (or vice versa) based on your root font size. Includes a common-sizes table with live preview. Runs entirely in your browser. PX to REM Converter on 712 Tools runs entirely inside your browser using modern JavaScript APIs — no server ever sees your data. That means instant results, complete privacy, and no upload limits.

Whether you need to convert between pixels and rem units for responsive css for a debugging session, a quick sanity check, or a production incident, this tool is free to use as many times as you need. There are no watermarks, no sign-up, and no ads inside the tool itself.

Frequently asked questions

Why use REM instead of PX?

REM scales with the user's root font size — so users who bump their browser text size get a larger layout too. Better accessibility with no extra work.

What about EM?

EM is relative to the parent element's font size — useful for internal component scaling but confusing across a whole layout. REM is relative to the root only.

What if my root is 62.5%?

That's the 'REM = 10px' trick — set root font-size to 62.5% and 1rem = 10px. Change the base field to 10 in this tool.