Modern responsive web design uses relative CSS units like rem and em instead of fixed pixels. The rem unit is relative to root element's font size (typically 16px), making it ideal for scalable, accessible designs. Converts between px, rem, em, and pt with custom base font size.
Browser default is 16px
| PX | REM | PT |
|---|---|---|
| 8px | 0.5rem | 6pt |
| 10px | 0.625rem | 7.5pt |
| 12px | 0.75rem | 9pt |
| 14px | 0.875rem | 10.5pt |
| 16px | 1rem | 12pt |
| 18px | 1.125rem | 13.5pt |
| 20px | 1.25rem | 15pt |
| 24px | 1.5rem | 18pt |
| 32px | 2rem | 24pt |
| 48px | 3rem | 36pt |
| 64px | 4rem | 48pt |
Enter a value in px or rem, and all conversions appear instantly. Set your base font size (default 16px) for accurate calculations. Toggle between px-to-rem and rem-to-px modes. Copy button for each result. Quick value buttons for common pixel sizes.
CSS unit conversion for responsive web design. Convert pixel-based designs from Figma or Sketch to rem-based CSS for scalable layouts. Convert legacy px-based stylesheets to rem units. Convert print measurements (pt) to screen units (px). Ensure consistent sizing across viewports and user font preferences.
Conversion formulas: px to rem = px / baseFontSize, rem to px = rem × baseFontSize, px to pt = px × 0.75 (72 DPI / 96 DPI), percent = (rem × 100)%. Em values shown assume root context (equivalent to rem). Default browser font size is 16px, but users can change this in settings, which is why rem-based designs are more accessible. Supports custom base font sizes.
Divide the pixel value by the root font size (default is 16px). For example, 24px ÷ 16 = 1.5rem. This tool does the calculation automatically for any base font size you set.
rem is relative to the root element's (<html>) font size and stays consistent throughout the page. em is relative to the parent element's font size and can compound when nested. rem is generally preferred for predictable sizing.
Using rem respects the user's browser font size settings, improving accessibility. If a user increases their default font size from 16px to 20px, all rem-based sizes scale proportionally, while px values remain fixed.
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