Convert between px, rem, em, pt, and % with a configurable base font size.
rem is relative to the root element's font size. em here assumes the same base as rem for simplicity — in real CSS, em is actually relative to the parent element's font size, not a fixed root value. pt uses the standard 96px/72pt-per-inch ratio (1pt = 4/3px). % is relative to the base font size above.
Equivalent values