Color Contrast Ratio Calculator
Color Contrast Ratio
Calculate WCAG color contrast ratio from luminance.
Formula
Ratio = (L1 + 0.05) / (L2 + 0.05)
Frequently Asked Questions
What contrast ratio is needed for WCAG AA?
4.5:1 for normal text and 3:1 for large text.
What is relative luminance?
A measure of light intensity from 0 (black) to 1 (white).