CSS Unit Converter
Unit options
rem uses the base font size. em and % use the parent size. vw and vh use the viewport width and height.
Live preview
About CSS Unit Converter
CSS Unit Converter helps convert common CSS units like px, rem, em, %, vw, and vh. It is useful when adapting typography, spacing, breakpoints, and responsive layouts.
You can change the base font size, parent size, viewport width, and viewport height to match your project context instead of relying on fixed assumptions.
How to use it
- Enter the value you want to convert.
- Choose the source and target CSS units.
- Adjust base font size, parent size, or viewport values when needed.
- Copy the converted value or CSS rule.
Tips
- Use 16px as the common default base size for rem conversions.
- Use parent size when converting em or percent values.
- Use viewport width for vw and viewport height for vh conversions.
- Check the preview to understand the visual scale of the converted value.
Related guides
Learn the workflow behind this tool and what to check next.
Technical SEO checks before submitting a site
A focused checklist for making sure search engines can discover, crawl, understand, and index important pages.
How to debug API JSON responses
Format the response, confirm the HTTP status, validate the schema, and compare payload changes before changing application code.
Privacy and usage
Built for quick checks without an account
Toolinix tools are designed for short developer tasks: paste a safe sample, inspect the result, copy what you need, and move on.
No login required
You can use the tools without creating an account, subscribing to a newsletter, or saving a workspace.
Local when possible
Formatters, generators, encoders, and text utilities generally run in your browser. Network diagnostics may need a server-assisted lookup to check public URLs, domains, or IPs.
Keep secrets out
Do not paste production passwords, private keys, access tokens, customer records, or regulated data into online tools unless your own security policy allows it.
Related tools
You may also find these tools useful.