Font Size Converter

Convert font sizes between px, pt, em, rem and % against any root size — with a live conversion table for common values. Fast, exact, and runs in your browser.

100% private — runs entirely in your browser. Your files never leave your device.

100% private — runs in your browser
pxptemrem%

em, rem and % are calculated against the root font size (default 16 px). em and rem share that base here — in real CSS, em is relative to the element’s parent while rem is always relative to the root. pt uses the CSS reference of 96 px = 72 pt. Click any result to copy it.

How to use the Font Size Converter

  1. Enter your value and choose its unit (px, pt, em, rem or %).
  2. Set the root font size (default 16px).
  3. Read the converted values in every unit.
  4. Click any result to copy it.

What you can use it for

  • Convert design specs from px to rem for CSS
  • Match print point sizes to on-screen pixels
  • Build accessible, scalable type systems
  • Translate values between design tools and code

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Frequently asked questions

How do I convert px to em or rem?

Enter your pixel value and root font size (default 16px). em and rem are the pixel value divided by the root size — e.g. 24px ÷ 16 = 1.5rem.

What's the difference between em and rem?

rem is always relative to the root (html) font size; em is relative to the element's own parent. This tool uses one root base for both — see the note under the tool.

How are px and pt related?

CSS defines 96px = 72pt, so 1pt ≈ 1.333px and 1px = 0.75pt. The converter uses this reference.

Is this tool free and private?

Yes — it's free, needs no signup, and calculates everything locally in your browser.