Font Size Converter
Convert CSS font sizes between px, pt, em, rem, and %. Set your own base size.
px
16
pt
12
em
1
rem
1
%
100
em/rem and % depend on the base font-size (default 16px = browser default).
Convert CSS units instantly
Enter a value, pick its unit, and see px, pt, em, rem, and % side by side. em/rem and % are calculated against the base font-size (16px by default — the browser standard). Handy for translating designs into responsive CSS.
Frequently asked questions
How are em and rem calculated?
Both are relative to the base font-size. With the default 16px base, 1em = 1rem = 16px, and 2em = 32px. Change the base to match your project's root font-size.
What's the px-to-pt formula?
On the web, 1pt = 96/72 px (≈1.333px), so 12pt = 16px. This tool uses that CSS convention.
Is it free?
Yes, completely free with no signup. It runs in your browser.