Convert CSS pixels to REM, EM, and Percentage units effortlessly. Build accessible, responsive websites with the correct relative units.
In modern web development, using relative units like REM (Root EM) is crucial for accessibility. Pixels (px) are fixed units. If a user sets their browser's default font size to be larger (e.g., for visual impairment), pixel-based layouts won't scale correctly.
The calculation is simple: Pixels / Base Size = REM.
Relative to the root (html) element font size. Consistent across the entire page. Best for font sizes, margins, and padding.
Relative to the parent element's font size. Good for component-level scaling (e.g., padding inside a button scaling with the button text).
Essential for Frontend Devs.
Modern CSS frameworks rely heavily on REM units. For example, Tailwind's `text-lg` is `1.125rem` (18px) and `w-4` is `1rem`. Use this tool to translate your Figma pixel values into framework-friendly units.
Looks good on all devices.
This is a common trick (16px * 62.5% = 10px) to make math easier (e.g., 1.4rem = 14px). However, modern development often prefers sticking to the 16px standard to avoid confusion with third-party libraries.
Yes, browsers can render sub-pixel values (e.g., 14.5px). This tool supports decimal inputs for precise conversion.