Converters
REM to Percent Converter
Convert REM values into percentages for scalable and flexible CSS designs.
.element {
font-size: %; /* 1rem with 16px root */
}| REM | Percent | Common Use |
|---|---|---|
| 0.75rem | 75% | Small text, footnotes |
| 1rem | 100% | Base body text |
| 1.25rem | 125% | Large text, subheadings |
| 1.5rem | 150% | H3 headings |
| 2rem | 200% | H2 headings |
| 3rem | 300% | H1 headings |
Converting REM units to percentage values is a common task in responsive web design. This converter helps you quickly transform REM values to their equivalent percentage values based on the root font size.
What are REM Units?
REM (Root EM) is a unit of measurement in CSS that represents the font size of the root element (typically the <html> element). By default, browsers set the root font size to 16px, so 1rem equals 16px unless otherwise specified.
What are Percentage Units?
Percentage (%) units in CSS are relative to the parent element's size. For font sizes, percentages are relative to the parent element's font size. 100% represents the same size as the parent.
Conversion Formula
To convert from REM to percentage:
percentage = (rem × root_font_size × 100) ÷ 16
Where:
- rem is the REM value you want to convert
- root_font_size is the font size of the root element (default: 16px)
- 16 is the default browser font size in pixels
When to Use Percentage Instead of REM
Percentage units are useful when you want an element's size to be relative to its parent rather than the root element. This is particularly helpful for:
- Creating nested components with relative sizing
- Building fluid layouts that adapt to container sizes
- Setting font sizes that scale with their parent elements
- Creating responsive designs that maintain proportions
Browser Support
Both REM and percentage units have excellent browser support across all modern browsers, including mobile browsers. They are safe to use in production environments.