CSS Unit Converter

Convert px, em, rem, pt, percentages and viewport units. Set font sizes and reference dimensions for accurate CSS length calculations.

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FromToLocal font (px)Root font (px)Viewport width (px)Viewport height (px)Percentage reference (px)

Enter a value · px

Up to 200,000 characters. Processed locally.

Result

0 UTF-16 units

0Words

0Characters

0Without spaces

0Lines

How it works

Paste your content or load the example. Choose the available options, run the tool, then copy or download the result.

A practical example

Enter a value · px

Result

2 rem

Frequently asked questions

Is my input sent to a server?

No. Your content is processed in this browser. It is never sent to the server or saved.

What should I know about CSS Unit Converter?

Absolute CSS lengths use 96 px per inch. em uses the supplied local font size; rem uses the root font. Percentages use your chosen reference dimension, not an inferred CSS property. vw/vh refer to the entered viewport. Results are rounded to six decimal places.