Convert pixel values to rem units instantly. Supports custom base font size.
REM (Root EM) is a CSS unit relative to the root element's font size. Unlike PX which is fixed, REM scales with user browser settings — making it essential for accessible, responsive design.
The formula is simple: divide the pixel value by the base font size.
rem = px ÷ base font size
Example: 24px ÷ 16px base = 1.5rem
REM units respect user font size preferences set in the browser, improving accessibility. They also make global scaling easy — change the root font size and everything scales proportionally.