Free PX to REM Converter
Convert pixel measurements to CSS REM units based on custom root font sizes.
How to Use Instructions:
- Enter your target pixel value in the Pixels (PX) input field.
- Set your project's root font size in Base Font Size (PX) (default is 16px).
- Copy the automatically calculated REM value displayed in the result box below.
Related Free Tools
Continue with related JunctionTools utilities: Base64 Converter · JSON Formatter · Regex Tester.
About This Tool
Convert CSS pixel values to rem units using a configurable root font-size. This is useful when building scalable typography, spacing and responsive design systems.
How to Use It
Enter the pixel value and the root font-size used by your CSS, then review the equivalent rem value. Use the same root assumption as the project when converting values.
How It Works
The conversion is rem = pixels ÷ root font-size. For example, with a 16px root, 32px equals 2rem. The mathematical result is independent of viewport size.
Practical Example
A design system using a 16px root can convert a 24px spacing value to 1.5rem. If the root changes, the equivalent rem value for the same pixel measurement changes too.
Frequently Asked Questions
Does this guarantee production correctness? No. Validate important results in the actual browser, application or search environment.
Can automated validation replace expert review? No. It identifies detectable issues but context and platform-specific requirements still matter.