CSS px to rem Converter

Convert CSS pixel units (px) to relative root em units (rem) based on root font size.

How It Works & Processing Standards

Enter values above to calculate results automatically. Check each input field for guidance and units.

Example: value=32, direction=pxToRem, rootFontPx=16 → 2

Your input data is never sent to any server and is securely processed on your device.

Current Limits

  • Maximum input length: 100,000 characters

CSS px to rem Converter is a 100% free, browser-based online utility. All calculations and file conversions run locally inside your browser (Local-First) without sending data to remote servers, keeping your documents and inputs strictly private.

How to Use CSS px to rem Converter

  1. 1
    Enter ValueType pixel or rem measurement.
  2. 2
    Choose DirectionSelect px → rem or rem → px.
  3. 3
    Set Root Font SizeSet base html font size (typically 16px).

Common Use Cases

  • Converting Figma pixel design handoffs into responsive rem CSS stylesheets
  • Building accessible web typography systems that scale with user font settings
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