About this tool
Convert a CSS length between px, rem, em, pt, %, vw and vh using your base font size and viewport.
Everything is converted through pixels: 1 rem = root font size, 1 em = parent font size, 1 pt = 4/3 px, 1 vw = 1% of the viewport width, 1 vh = 1% of its height, % is relative to the parent font size.
Formula: px = rem × root · pt = px × 0.75
Example: Value = 24, From unit = px, Root font size (px) = 16, Parent font size (px) = 16, Viewport width (px) = 1,440, Viewport height (px) = 900 → px = 24, rem = 1.5.
Browsers default to 16 px for the root font size unless the page or user changes it.
Quick steps
- Enter your values — every field shows its unit.
- Press Calculate (or Try an example to see how it works).
- Read the results and copy them if you need them elsewhere.
The calculation runs in your browser. Nothing you type is sent to 1CLIK.
FAQ
How does the CSS Unit Converter (px, rem, em, pt, vw) work?
Everything is converted through pixels: 1 rem = root font size, 1 em = parent font size, 1 pt = 4/3 px, 1 vw = 1% of the viewport width, 1 vh = 1% of its height, % is relative to the parent font size.
What should I keep in mind?
Browsers default to 16 px for the root font size unless the page or user changes it.
Is my data sent anywhere?
No. The numbers stay on your device; the page only shows the result.