Default: 16px
| Unit | Equals (in px) | Description |
|---|---|---|
| 1px | 1px | Pixel (absolute) |
| 1rem | 16px | Root element font-size |
| 1em | 16px | Parent element font-size |
| 1pt | 1.33px | Point (1/72 inch) |
| 1in | 96px | Inch |
| 1cm | 37.8px | Centimeter |
| 1vh/vw | Varies | 1% of viewport height/width |
Yes, completely free with no sign-up. Convert between all CSS units as many times as you need.
No, all conversions happen in your browser. Your values are never sent to any server.
Type the value you want to convert in the input field (you can include the unit or just the number). Select the unit you are converting from (px, rem, em, pt, cm, mm, in, pc, vh, vw, or %). For rem and em conversions, set the base font size (typically 16px). View your value converted to all other CSS units simultaneously. Click the copy button next to any converted value to use it in your CSS.
REM is relative to the root font size (usually 16px), while EM is relative to the parent element font size. REM is more predictable for consistent sizing.
REM units respect user font size preferences for better accessibility. They also make responsive design easier since all sizes scale proportionally.