About the PX to REM Converter
Rem units scale with the root font size, so a layout built in rem respects the reader’s browser settings instead of overriding them. Dividing your pixel value by the root font size — 16px in every browser by default — gives the rem equivalent.
Also known as: pixel to rem, px rem converter, rem calculator, css rem units.
How to use this calculator
- Enter pixels, root font size.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
rem = pixels ÷ root font size
Worked example
Using the values pre-filled in the calculator above:
- Pixels = 24 px
- Root font size = 16 px
the calculator returns:
- In rem: 1.5 rem
- CSS value: 1.5rem
- Rounded to 3 decimals: 1.5rem
- Back to pixels: 24 px