What is a PX to REM Converter?
rem units respect the user’s font-size preference — the accessibility reason design systems specify type and spacing in rem while designers hand off pixels.
Convert any pixel value at any root size, with the common-values table you will otherwise re-derive weekly.
How to use the PX to REM Converter
- Enter the pixel value.
- Adjust the root size if yours differs from 16px.
- Read the rem value and the reference table.
Frequently asked questions
Why rem instead of px?
Users who raise their browser font size get proportionally larger text and spacing with rem; px ignores their preference.
rem vs em?
rem is relative to the root (predictable); em is relative to the parent (compounds down the tree). Default to rem.
What is the 62.5% trick?
Setting html{font-size:62.5%} makes 1rem = 10px for easy math — at the cost of surprising every third-party stylesheet. Most teams skip it now.
Should borders be rem too?
Hairline borders usually stay px on purpose — you rarely want a 1px border scaling.