๐จ CSS Unit Converter
๐ Conversion Results
๐๏ธ Visual Preview
Size: 0px ร 0px
๐ Quick Reference Chart
| Unit | Type | Relative To | Common Use |
|---|---|---|---|
| px | Absolute | Screen pixels | Fixed sizes |
| em | Relative | Parent font size | Scalable typography |
| rem | Relative | Root font size | Consistent scaling |
| % | Relative | Parent element | Responsive layouts |
| vw | Relative | Viewport width | Responsive widths |
| vh | Relative | Viewport height | Full-height sections |
โ Frequently Asked Questions
What's the difference between em and rem?
Em units are relative to the parent element's font size, while rem units are relative to the root (html) element's font size. Rem provides more consistent scaling across your design.
When should I use viewport units (vw/vh)?
Viewport units are perfect for creating truly responsive designs that scale with the browser window. Use vw for widths that should scale with viewport width, and vh for heights relative to viewport height.
How do percentage units work in CSS?
Percentage units are relative to the parent element's dimensions. For width, it's relative to parent's width; for font-size, it's relative to parent's font-size.
What's the standard base font size?
Most browsers default to 16px as the base font size. This means 1rem = 16px by default, unless you change the root font size.
Should I use absolute or relative units?
For responsive design, prefer relative units (rem, em, %, vw, vh). Use absolute units (px) only when you need fixed sizes that shouldn't scale.
How do print units (pt, pc, in, cm, mm) work on screens?
Print units are converted to pixels based on assumed DPI (dots per inch). 1in = 96px, 1cm = 37.8px, 1mm = 3.78px, 1pt = 1.33px, 1pc = 16px.
What's the best unit for responsive typography?
Use rem for consistent scaling, or combine rem with vw using calc() for fluid typography. Example: font-size: calc(1rem + 1vw).
How can I test my conversions?
Use browser developer tools to inspect elements and see computed values. The visual preview in this tool also helps you understand the actual rendered size.