Free · no signup · browser-local
CSS PX to REM Converter with Custom Root Font Size
Enter a pixel value and your site's root font size to calculate the equivalent CSS rem value. For example, 24 px at a 16 px root equals 1.5 rem.
Input and settings
LOCAL1.5 rem 24 px at 16 px root
Getting started
Enter pixels and the root font size, then inspect rem.
Before you use the result
The root size is project-specific and can change with user settings.
Try an example
At a 16 px root, 24 px equals 1.5 rem.
How it works
rem equals pixels divided by root font size.
Frequently asked questions
Convert CSS pixels and rem against an explicit root font size.
How do I use PX to REM Converter?
Enter pixels and the root font size, then inspect rem.
Does this tool upload my data?
Inputs and files are processed in your browser. Page-view analytics do not contain your tool input.
What should I check before using the result?
The root size is project-specific and can change with user settings.