Convert px, em, rem, pt & % — plus clamp() and type scales
This free font size converter helps web developers and designers quickly convert between different CSS font size units. Whether you're working with pixels (px), em units, rem units, points (pt), or percentages, this tool provides instant conversions with a live preview. It also generates responsive clamp() values and modular type scales.
How to use: Simply enter a value in any unit, and see instant conversions to all other units. Adjust the base font size for accurate em/rem calculations, and click any result to copy it to your clipboard.
Base font size affects em/rem calculations. Standard browser default is 16px.
The quick brown fox jumps over the lazy dog
Font size: 16px
| Pixels | Em | Rem | Points | Percent |
|---|
Generate a fluid CSS font-size that scales smoothly between a minimum and maximum size across viewport widths. Output uses rem (relative to your base font size) so it respects user zoom.
font-size: clamp(...);
The quick brown fox jumps over the lazy dog
Build a harmonious set of font sizes from a base size and a ratio. Each step multiplies (or divides) the previous size by the ratio. Click any row to copy its value.
:root { ... }
Precise calculations based on standard web typography ratios
See how your font size looks in real-time as you convert
Click any converted value to instantly copy it to your clipboard
Create fluid, responsive font sizes with CSS clamp() in one click
Generate harmonious size scales from musical ratios & the golden ratio
Works perfectly on all devices - phones, tablets, and desktops
