CSS Unit Converter

Convert between CSS units with context awareness: px, em, rem, viewport units, and more for responsive design.

Unit Input & Context
Enter a value and configure context settings
Input

For em, ex, ch

For rem unit

For vw, vmin, vmax

For vh, vmin, vmax

Conversion Results
Converted values in all CSS unit formats

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Enter a value to see all unit conversions

CSS Unit Guide

Absolute Units

  • px: Screen pixels (most common for web)
  • pt: Points, 1/72 inch (print design)
  • pc: Picas, 12 points (typography)
  • in/cm/mm: Physical measurements

Relative Units

  • em: Relative to element's font-size
  • rem: Relative to root font-size
  • ex: Height of lowercase 'x'
  • ch: Width of '0' character

Viewport Units

  • vw: 1% of viewport width
  • vh: 1% of viewport height
  • vmin: 1% of smaller dimension
  • vmax: 1% of larger dimension

Best Practices

  • • Use rem for font sizes (accessibility)
  • • Use em for component spacing
  • • Use px for borders and shadows
  • • Use vw/vh for full-viewport elements
  • • Avoid fixed pixel heights when possible
  • • Test with different browser zoom levels

Responsive Design Tips

  • • Combine different unit types strategically
  • • Use rem for consistent scaling
  • • Use vw for fluid typography
  • • Consider clamp() for responsive values
  • • Test on various devices and screen sizes
  • • Always consider accessibility requirements