Enter a value and pick px, pt, em, rem, mm, cm, vw, or vh, and the tool converts it to every other typography unit live.
At the standard 96 DPI screen resolution, 1 point (pt) = 1.333 pixels (px).
1em is relative to the parent element's font size, while 1rem is always relative to the root (html) font size — commonly 16px by default.
Divide pixels by the root font size (usually 16). So 24px = 1.5rem at a 16px root.