How it works
One division
A rem is the font size of the page's root element. Divide pixels by that size to get rem, multiply rem by it to get pixels. Browsers set the root to 16px unless the user or your stylesheet changes it.
Results keep at most four decimals with trailing zeros dropped, so 24px at a 16px root reads 1.5rem and 11px reads 0.6875rem.
rem = px ÷ root size; px = rem × root size
Switching direction
Switching between PX → REM and REM → PX carries the current result into the field, so the pair on screen stays the same. The up and down keys step by 1px or by a quarter rem.
The sample and the table
The sample sets the letters at the converted pixel size over a ruled grid, one line per rem (spaced at least 4px apart for tiny roots). The table lists common pixel sizes at your root; pick a row to load it.
