px to rem converter
Convert px to rem for any base font size. The output updates as you type, with a reference table covering common values.
Try 16, 24, 1.5
Updates as you type
Default 16px — change to match your project.
How to use this tool
- 1Enter the px value you want to convert.
- 2Set your project’s base font size (defaults to 16px).
- 3Read the rem equivalent and copy it for your stylesheet.
About this tool
Pixels are absolute; rem values scale with the user’s root font size, which is why design systems and accessibility-conscious sites prefer rem for spacing and typography. The default browser root is 16px, so 1rem = 16px unless you’ve changed it.
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Frequently asked questions
What base font size does this converter use?
The default is 16px, which is the browser default for the root `html` element. You can change the base in the input below to match your project (for example, some designs use 10px so 1rem = 10px).
Why use rem instead of px?
rem is relative to the root font size, so the entire interface scales when the user adjusts their browser font size. That matters for accessibility and is a key reason design systems use rem for spacing and typography.
Is the conversion exact?
Yes. With the base font size you specify, the conversion is a simple multiplication or division. The math is the same as what your browser does at runtime.
Does this work offline?
Conversion runs entirely in your browser. No values are sent anywhere, and once the page loads, it works offline.
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