CSS Unit Converter Online - Free px to rem, em, vw Calculator
Free online CSS unit converter. Convert between px, rem, em, vw, vh, pt, cm, mm and more with configurable base font size.
Used for rem, em, and % calculations
Common CSS Unit Conversions
| Unit | Description | Example |
|---|---|---|
| px | Pixels (absolute) | 16px |
| rem | Root em (relative to html font-size) | 1rem = 16px (default) |
| em | Relative to parent element font-size | 1em = parent font-size |
| vw | Viewport width (1vw = 1% of viewport width) | 50vw = half screen width |
| vh | Viewport height (1vh = 1% of viewport height) | 100vh = full screen height |
| % | Relative to parent element | 50% = half parent width |
| pt | Points (typography, 1pt = 1.333px) | 12pt |
| cm/mm/in | Physical units (rarely used in web) | 2.54cm = 1in = 96px |
CSS Unit Converter
Convert between all CSS units instantly.
Features
- All CSS units supported
- Configurable base font
- Viewport dimension control
- Quick presets
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☕Buy Me a CoffeeHow to Use CSS Unit Converter
- Paste or upload your input data into the CSS Unit Converter input area
- Select the desired output format or conversion options
- Click Convert to transform your data instantly
- Copy the converted result or download the output file
Common Use Cases
- Converting pixel values to rem for responsive design
- Switching between em and px for typography
- Calculating viewport-based units from pixel values
- Building consistent spacing systems with unit conversions