Font Size Converter

Convert between px, rem, em, and pt — with live preview

Base font size: px (browser default is 16px — change if your root font-size is different)
Pixels
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Click to copy
rem
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Click to copy
em
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Click to copy
pt (points)
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Click to copy
Percent (%)
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Click to copy
Approx. vw (1920px)
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Based on 1920px viewport
Live Text Preview
The quick brown fox jumps over the lazy dog
Font size: --
Common Font Sizes
How to Use the Font Size Converter
1
Set your base font size — 16px is the browser default (change only if your CSS sets a different root size)
2
Enter the font size value and select the unit you are converting FROM
3
See instant conversions across all units — click any result to copy the CSS value
4
Check the live preview to see how the font size renders in the browser
About This Font Size Converter

Our font size converter helps web developers and designers quickly convert between CSS font size units. The most important conversion is between px (absolute pixels) and rem (relative to root element) — rem is preferred in modern CSS because it respects user browser settings and improves accessibility.

rem vs em: rem is relative to the root HTML element's font size (usually 16px). em is relative to the parent element's font size, which can compound in nested elements. For font sizes, rem is generally safer and more predictable than em.

Frequently Asked Questions
1rem = 16px by default in most browsers. If the root font-size is set to 16px, then 1rem = 16px, 0.875rem = 14px, 1.5rem = 24px. Change the base size above if your project uses a different root size.
Use rem for font sizes in modern web projects. rem respects user browser font size preferences (accessibility), scales predictably, and works well with responsive design. px is absolute and ignores user settings.
12pt = 16px on screen (at 96 DPI). 1 point = 1.333px at 96 DPI. So 12pt × 1.333 = 16px. Note: pt units are more accurate for print design; for screen use px or rem instead.