Convertisseur d'Unités CSS

Convertissez n'importe quelle valeur CSS entre px, rem, em, vw, vh, %, pt, pc, ch, ex, cm, mm et in. Définissez votre taille de police de base et les dimensions du viewport pour une conversion précise en temps réel. 100% côté client.

Valeurs Converties

Unité Valeur Action

About CSS Unit Converter

Our free CSS Unit Converter helps web developers and designers instantly convert between all common CSS units. Whether you need to convert px to rem for responsive design, vw to px for viewport-relative sizing, or any other combination — this tool handles it all. All calculations happen in your browser with no data sent to servers.

Features

  • Convert between 13 CSS units: px, rem, em, vw, vh, %, pt, pc, ch, ex, cm, mm, in
  • Real-time conversion as you type — no page reload needed
  • Customizable base font size for accurate rem/em conversions
  • Viewport dimensions for precise vw/vh calculations
  • One-click copy for any converted value
  • 100% client-side — your data stays completely private

Frequently Asked Questions

How do I convert px to rem?

Set your base font size (default is 16px), enter your pixel value, select "px" as input, and the converter will instantly show the rem equivalent. For example, 16px = 1rem when the base font size is 16px.

What is the difference between em and rem?

Both em and rem are relative units based on font size. "rem" (root em) is always relative to the root element font size (usually <html>). "em" is relative to the font size of the parent element. This makes rem more predictable for consistent sizing across components.

How does vw and vh work?

vw (viewport width) and vh (viewport height) are relative to the browser window size. 1vw = 1% of the viewport width, and 1vh = 1% of the viewport height. They are perfect for creating responsive layouts that adapt to screen size.

Is my data private?

Absolutely. All conversions happen entirely in your browser. No data is ever sent to our servers or stored anywhere.