CSS Unit Converter
Convert pixels to rem/em units for responsive CSS. Perfect for converting Figma designs to scalable web layouts.
About CSS Unit Converter
The CSS Unit Converter is an essential tool for modern web developers who need to convert pixel values from design tools like Figma, Sketch, or Adobe XD into responsive rem and em units. This conversion is crucial for creating accessible, scalable web designs that adapt beautifully across different devices and user preferences.
How CSS Unit Conversion Works
CSS unit conversion is based on a simple mathematical relationship between pixels and relative units:
- REM units: Relative to the root element's font size (typically 16px)
- EM units: Relative to the parent element's font size
- Conversion formula: rem/em = pixels ÷ base font size
- Example: 24px ÷ 16px = 1.5rem
Key Features
Single Conversion
Convert individual pixel values to rem and em units with instant results and one-click copying.
Batch Processing
Paste entire CSS blocks and convert all pixel values at once, perfect for large design systems.
Customizable Base Size
Adjust the base font size to match your project's root font size for accurate conversions.
Conversion Table
Quick reference table for common design measurements and typography scales.
Common Use Cases
- Figma to CSS: Convert design measurements to responsive units
- Typography scaling: Create consistent font size hierarchies
- Spacing systems: Convert margins and padding to scalable units
- Component dimensions: Make UI components responsive and accessible
- Design system migration: Convert existing pixel-based designs to rem/em
Best Practices for CSS Units
When to Use REM vs EM
- Use REM for: Font sizes, margins, padding, and layout dimensions
- Use EM for: Component-specific spacing that should scale with the component
- Use PX for: Borders, box shadows, and elements that shouldn't scale
Pro Tips for Responsive Design
Accessibility First: Using rem units ensures your design respects user font size preferences, improving accessibility for users with visual impairments.
Consistent Base: Stick to a 16px base font size unless you have specific requirements, as it's the browser default and most accessible.
Design System Integration: Use this tool to create consistent spacing and typography scales that work across your entire design system.
Conversion Examples
Start converting your pixel-based designs to responsive, accessible CSS units today. Simply enter your pixel values above and get instant rem and em conversions that will make your web designs more flexible and user-friendly.