Browser-only calculator

PX to REM Converter

Convert a single CSS value or a space-separated list while preserving useful precision.

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Browser-only processingCalculations are performed locally in your browser. Your entered values are not sent to our servers.

PX to REM Converter formula

rem = px ÷ root font size. px = rem × root font size.

Worked example

At a 16px root size, 24px equals 1.5rem.

How to use this calculator

  1. Choose the conversion direction.
  2. Enter one or more numeric values.
  3. Copy the converted CSS values.

Important assumptions and limitations

The root font size must be greater than zero.

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Frequently asked questions

What root size should I use?

Browsers commonly default to 16px, but use your project’s actual root size.

Can I convert several values?

Yes. Separate values with spaces or commas.