PX ↔ REM / EM Converter

Live-convert between pixel and relative CSS units with a configurable root font size.

Root Font Size (px)

Pixels (px)

REM

Quick Reference Table

PX vs REM

px is an absolute unit. rem is relative to the root <html> font-size (default 16px). em is relative to the parent element's font-size. Using rem ensures consistent sizing across components and respects user browser zoom settings — a key accessibility best practice.