CSS Unit
Online CSS units converter tool.
Processes your input locally. Review generated configuration before publishing.
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What this tool does
Convert px, rem and em with supplied root and parent font sizes. Context-dependent units need the correct font-size assumptions.
How to use it
- Set amount (initial value: 16).
- Set from to one of: px, rem, em.
- Set to to one of: px, rem, em.
- Set root font size (px) (initial value: 16).
- Set parent font size (px) (initial value: 16).
- Choose Process, inspect the result, then use the download control. A reported error means no successful output was produced.
Limits and result checks
Processes your input locally. Review generated configuration before publishing.
Common questions
Why can the same em value have different pixel sizes?
An em is calculated from the supplied parent font size, while rem uses the supplied root font size. The tool cannot inspect the destination stylesheet; enter those sizes yourself.
Where can I read the data-handling details for CSS Unit?
Inputs are processed in browser memory and are not uploaded by this plugin. Generated downloads remain on your device. The site privacy policy explains memory cleanup and hosting logs.