Created by Katakata · Last reviewed
How to use PX to REM Converter
REM units scale from the document root and are useful for type and spacing systems that respect user settings. This converter handles both directions, makes the root size explicit, and turns selected values into reusable CSS, SCSS, or class snippets.
Practical workflow
- Confirm the root size used by your project. The browser default is commonly 16 px, but your stylesheet may override it.
- Enter a pixel or rem value; the other field updates from value ÷ root or value × root.
- Add recurring sizes to the reference table, choose an output format, and copy the generated tokens into your project.
Accuracy and limitations
Changing the root to 10 px for easier arithmetic can reduce expected browser scaling if implemented carelessly. Do not treat px as physically identical across screens. Test zoom, user font-size preferences, and long translated copy before adopting a scale.
Privacy and data handling
Conversions and custom scale values stay in the browser. The page does not upload your CSS or input values.
Why this page exists
KatakataLab publishes small browser tools built from recurring design and development tasks. This English page is maintained as a complete entry point, not as an automatic translation or a doorway page. If a control, explanation, or result is unclear, use the contact page and include the tool name, browser, and expected result without sending confidential input.
For another workflow, browse the English tool index or switch to the Japanese version.