Absolute vs Relative Units

This font size converter handles both families. Points and pixels are absolute — 1 pt equals 1/72 inch and 1 CSS pixel equals 1/96 inch, giving the exact 4:3 ratio. EM, REM, and percent are relative: they scale against a reference size rather than physical units.

Why REM for Accessibility

Root-relative sizing respects browser zoom and user font-size preferences. If a user sets their default to 18 px, a 1 rem headline scales up automatically, while a fixed 16 px size stays put. That makes REM the recommended unit for fluid, accessible type systems.

Converting Between Systems

Design tools default to points, the web defaults to pixels, and modern CSS prefers relative units. Convert through pixels as the common denominator: points to pixels first, then to em or rem using the relevant base size.