PX to REM Converter with 10px Base
Convert px to rem, rem to px and px to em at any base font size, with a copy-ready CSS line and a live reference table.
Processed entirely in your browser — nothing you enter here is ever uploaded.
Result
About this tool
This page opens the converter with the base font size preset to 10px. That is the classic html { font-size: 62.5% } setup: 62.5% of the 16px browser default is exactly 10px, so rem values become trivially readable — 14px is 1.4rem, 18px is 1.8rem, 24px is 2.4rem.
Teams adopt the 10px base precisely to avoid awkward sixteenths: instead of remembering that 14px is 0.875rem, you just move the decimal point. Because the trick uses a percentage rather than a fixed pixel value, it still respects the font size a user sets in browser preferences, which is the whole accessibility argument for rem units in the first place.
Type any pixel value to get its rem equivalent at the 10px base together with a copy-ready CSS line, and check the reference table below for the whole 1–64 px scale already converted. If your project uses a different root size, change the base field and everything follows live.
Example. 32 px with a base of 16 in px-to-rem mode returns 2 rem and a CSS line font-size: 2rem.
Limit. A base font size of 0 or blank is rejected, and the reference table only lists the 14 sizes from 1 px through 64 px.