Font Size Calculator
Convert between px, rem, em, pt, vw, vh, and % — with configurable root and context sizes.
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px
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Conversions (16 px)
| Unit | Value | Copy |
|---|---|---|
| px | 16px | |
| rem | 1rem | |
| em | 1em | |
| pt | 12pt | |
| vw | 1.11111vw | |
| vh | 1.77778vh | |
| % | 100% |
Common Tailwind sizes
CSS font size units explained
px is an absolute unit — always the same regardless of parent or settings. rem is relative to the root (html) font size (default 16 px). em is relative to the current element's inherited font size — so 1.5em inside a 20px context = 30px. pt is a print unit: 1pt = 96/72 px ≈ 1.333px. vw / vh are percentages of the viewport width/height.
For responsive typography that blends viewport and fixed sizes, try the CSS Clamp Calculator. For px↔rem with more context see px to rem Converter and CSS Unit Converter.
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