Web Design & Dev
PX to REM Converter
Convert between px and rem using any root font size.
Runs entirely in your browser — nothing you enter is sent or stored.
How it works
rem = px ÷ root font size. Browsers default to 16px, and users who enlarge their default font size get larger rem values too — which is exactly why rem is better for accessibility than fixed pixels.
Frequently asked questions
rem or em?
rem is relative to the root element and predictable everywhere; em is relative to the parent and compounds when nested. Use rem for most sizing.
Should I set html { font-size: 62.5% }?
It makes maths easier (1rem = 10px) but you must then reset body text. Many teams now keep 16px and use a converter.