Unit Converter
Convert PX, REM, EM, %
About CSS Unit Converter (PX, EM, REM, %)
1What is it?
Accurately convert CSS units for responsive web design. Switch between absolute pixels (px) and relative units like REM, EM, and Percentages. Features a customizable base font size setting to ensure your conversions match your specific project framework.
2Use Cases
- Modernize legacy CSS by converting fixed pixels to REMs
- Calculate precise percentage widths for fluid grids
- Standardize font sizes across a component library
- Translate Figma designs (usually px) to responsive CSS
3Examples
16px to REM
Input
16px (Base 16)
Output
1rem
?Frequently Asked Questions
Why is the Base Size important?
REM and EM values are multipliers of a base font size (usually 16px in browsers). If your project uses a different base (e.g., 10px or 14px), you must adjust this setting for accurate conversion.
Which unit is best for accessibility?
REM and EM are better than Pixels (PX) because they respect the user's browser font preferences. If a user scales up their text for readability, REM-based layouts scale with it, while PX might stay fixed.