CSS Unit Converter
Convert between 23 CSS units (px/em/rem/pt/%/ch/vmin/vmax/dvw/cqw…) with property context + comparison table. Free, offline, client-side, instant.
Convert one CSS value into 23 units simultaneously - including modern dvw / dvh / svw / lvh (dynamic viewport, 2022+) and cqw / cqh (container queries, 2023+). Property-aware % conversion and real viewport detection based on your actual browser window.
Context settings
All 23 unit conversions
How to Use CSS Unit Converter
- Enter a value and pick the source unit.
- For
%conversion, pick the property context (font-size, width, or height) - they use different bases. - Adjust root font-size (default 16px) for rem accuracy, and parent font-size for em accuracy.
- Pick a viewport preset (mobile / tablet / desktop / 4K) or override W/H - affects vw / vh / vmin / vmax / dvw / dvh / svw / svh / lvw / lvh.
- For container query units (cqw / cqh, 2023+), set explicit Container W/H - they default to viewport when blank.
- Read all 23 unit values in the comparison table. Click 📋 on any row to copy that specific value.
- Copy all 23 or download CSV for spreadsheet analysis.
Frequently Asked Questions
What does the CSS Unit Converter do?
It runs the css unit converter right in your browser, so you get the result instantly without uploading anything.
Is it free to use?
Yes. The tool is completely free, with no signup, no limits and no watermarks.
Does my data stay private?
Yes. Everything is processed locally in your browser, so the data you enter never leaves your computer.
Does it work offline?
Yes. Once the page has loaded you can disconnect and keep using it, since it does not rely on a server.
Do I need to install anything?
No. It works in any modern browser on desktop or mobile, with nothing to download or install.
Is there a limit on input size?
There is no fixed limit. Very large inputs simply take a little longer, since the work happens on your device.