PX to REM Converter
Convert absolute pixels to relative REM units for accessible, responsive typography.
About PX to REM Converter
The PX to REM converter is an essential tool for modern web developers creating accessible and responsive websites. This calculator converts absolute pixel values to relative REM (Root EM) units based on the root font size. REM units are preferred in responsive design because they scale relative to the root element's font size (typically 16px by default), making websites more accessible and easier to maintain. Simply enter your pixel value and optionally specify a custom root font size to get instant REM conversions.
Formula
Examples
Reference
- • 1 REM = Root element font size (default: 16px in most browsers)
- • Standard root font size: 16px
- • REM units are relative to the <html> element's font-size
- • W3C CSS Values and Units Module Level 3 specification
- • REM provides better accessibility than fixed pixel values
Frequency Asked Questions
What does REM stand for in CSS?
REM stands for 'Root EM' and represents a unit relative to the root element's font size. Unlike EM units which are relative to the parent element, REM is always relative to the root <html> element.
What is the default root font size for REM conversion?
The default root font size in most browsers is 16px. This means 1rem equals 16px by default, though users can change this in browser settings for accessibility.
Why use REM instead of PX?
REM units are better for responsive design and accessibility. They respect user font size preferences, scale consistently across the entire website, and make it easier to adjust typography globally by changing only the root font size.
How do I convert 16px to REM?
Using the formula REM = PX ÷ 16, we get: 16 ÷ 16 = 1rem. Since 16px is the default root size, 16px equals exactly 1rem.
Can I use decimal REM values?
Yes, REM values can be decimals. For example, 12px converts to 0.75rem, and 20px converts to 1.25rem when using the default 16px root size.
What if my root font size is not 16px?
Simply adjust the formula: REM = PX ÷ Your Root Font Size. For example, if your root is 10px, then 20px ÷ 10 = 2rem.