What Is REM?
REM (root em) is a CSS length unit relative to the font size of the <html> element. With the default 16px root, 1rem = 16px. Because every rem value derives from one root size, rem-based layouts scale consistently when users change their browser font preferences.
How REM to PX Conversion Works
Converting rem to pixels is multiplication. Take your rem value and multiply it by the root font size in pixels:
px = rem × root font sizeAt 16px root: 0.875rem → 14px, 1.25rem → 20px, 3rem → 48px. Designers publishing in rem often need pixel equivalents for image assets, media queries, or third-party widgets — this converter handles that instantly.
Common REM to PX Examples
0.5rem → 8px0.75rem → 12px1rem → 16px1.5rem → 24px2rem → 32px2.5rem → 40px4rem → 64px
When to Convert REM to PX
Prefer rem in your stylesheets for accessibility, but convert to px when matching a design mockup, sizing raster images, writing canvas code, or communicating with stakeholders who think in pixels. Keep the root at 16px unless your project explicitly overrides it.
REM vs PX for Developers
Use rem for typography, spacing and component sizing so your UI respects user settings. Use px for hairline borders, shadows and fixed decorative elements. This converter bridges both worlds so you can work in whichever unit your task requires.