Rem to Px Converter

Multiply the rem value by the root font size in pixels. With the browser default root of 16 px, 1 rem equals 16 px, 1.5 rem equals 24 px, and 2 rem equals 32 px. If your page sets a custom html font-size, enter that number as the root size to get an exact result.

Divide the pixel value by the root font size. At the default 16 px root, 24 px equals 1.5 rem and 10 px equals 0.625 rem. Because the formula is rem = px divided by root font size, a smaller root yields a larger rem number for the same pixels.

Browsers set the root element (html) font-size to 16 px by default, and 1 rem always equals that root size. So unless a stylesheet changes html { font-size }, 1 rem resolves to 16 px. Change the root font size field here to match your own CSS and every conversion updates instantly.

Setting html { font-size: 62.5% } makes the root 10 px, since 62.5% of 16 px is 10 px. After that, rem math is easy: 1.6 rem is 16 px, 2.4 rem is 24 px, and any pixel value divided by 10 gives the rem. Set the root font size to 10 px above to see this mapping in the reference table.

Rem is always relative to the root (html) font-size, so it stays consistent no matter where the element sits in the document. Em is relative to the font-size of the parent element, which can compound when elements nest. This tool converts rem, which depends only on the single root size, not on any parent context.

Rem scales with the reader's browser font-size preference, so text sized in rem respects accessibility settings and zoom. Pixels stay fixed regardless of that preference. Many designs size fonts and spacing in rem for accessibility while keeping borders and hairline details in px.