PX to REM Converter: CSS Unit Conversion Made Easy

# PX to REM Converter: CSS Unit Conversion Made Easy

The rem unit is the foundation of accessible, responsive CSS. But converting between pixels and rem in your head gets old fast — especially when your project uses a non-standard root font size. FreeToolJet's PX to REM Converter does the math instantly, with a quick reference table and one-click CSS copying.

The Formula

rem = px ÷ root font size

With the default browser root size of 16px: 24px = 1.5rem, 32px = 2rem, and so on.

Why Use rem Instead of px?

• Accessibility: rem respects the user's browser font-size setting. If someone increases their default from 16px to 20px, all your rem-based sizes scale proportionally.
• Consistency: rem creates a predictable scaling system. Set font-size: 1rem on the body and use multiples throughout.
• Responsive design: rem-based spacing and typography scale naturally across viewports.

When to Still Use px

• Borders (border: 1px solid)
• Box shadows and fine decorative details
• Canvas and SVG coordinates

Quick Reference (base: 16px)

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