px to rem converter — with a custom base
Convert pixel values to rem and back at any root font size. It calculates in your browser (0 uploads, works offline).
How to use it
- Enter your value in the field above.
- The result appears instantly.
- Copy or Download it.
FAQ
How do I convert px to rem for free?
Enter a pixel value and the rem equivalent appears instantly in your browser with no upload, based on a 16px root by default. Change the root font size or switch direction to convert rem back to px.
Why use rem instead of px?
rem scales with the user's root font size, so a layout in rem respects a reader's accessibility settings, while px is fixed. The converter helps translate a design spec in px into scalable rem values.
Is my data uploaded?
No. The calculation is local and nothing is stored; it works offline.
What if my base isn't 16px?
Set the root font size field to whatever your CSS uses and the conversion adjusts.
Limits
Converts single values. Batch conversion of a whole stylesheet is not included.
Related
The unit converter handles physical units; the color converter is another common CSS helper.
Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.