REM to Percent Converter

Convert REM units to Percentage (%) relative to parent.

150%

Enter Parent Font Size for typography, or Parent Dimension for Width/Height.

About REM to Percent Converter

The REM to Percent converter translates root-relative units into parent-relative percentage values, essential for creating flexible layouts that scale with container size. Percentages in CSS are context-dependent. This converter requires both the root font size and the parent context to calculate accurate percentage values from REM units.

Formula

Percent = ((REM × Root Size) ÷ Parent Size) × 100

Examples

1.5rem (16px root, 16px parent) = 150%
30rem (16px root, 1200px parent) = 40%

Reference

  • • Percentage font-size is relative to parent's font-size
  • • Percentage width/height is relative to parent's width/height
  • • Percentage padding/margin is relative to parent's WIDTH
  • • Percentages compound through nested elements

Frequency Asked Questions

How do percentage units work?

Relative to parent. Font-size relative to parent font, width relative to parent width.

Convert 2rem to % for font?

If parent matches root size: 200%.

REM vs Percentage?

REM for global consistency, Percent for component flexibility.

Do percentages respect user font size?

Not directly, unless parent uses relative units too.