Convert percentage values to REM units based on the root font size. Essential tool for accessible, responsive web design.
How Percentage to REM Conversion Works
REM (Root EM) units in CSS are relative to the root (html) element's font size. This tool helps you calculate the REM value that corresponds to a percentage of the base font size.
The formula used for conversion is:
remValue = (percentageValue / 100) × baseFontSizeInPixels / baseFontSizeInPixels
Which simplifies to:
remValue = percentageValue / 100
Example: If you have a value of 150% with a base font size of 16px, the REM value would be:
150% = (150 / 100) × 16px / 16px = 1.5rem
Why Use REM Units?
- Accessibility: REM units respect user font size preferences
- Consistency: All sizes are relative to a single base value
- Scalability: Easy to adjust sizing across the entire site by changing the root font size
- Responsive: Works well with media queries for different screen sizes
Common Use Cases:
- Converting legacy percentage-based designs to modern REM-based systems
- Creating accessible typography scales
- Building responsive components that respect user preferences
- Maintaining consistent spacing in design systems