MyCalcBuddy

Color Contrast Checker

Check color contrast ratios for WCAG 2.1 accessibility compliance. Ensure your text is readable.

Color Selection

Common Combinations

21.00:1

Normal text (16px)

Large text (24px or 18px bold)

WCAG 2.1 Compliance

Normal Text AA

Pass

Requires 4.5:1

Normal Text AAA

Pass

Requires 7:1

Large Text AA

Pass

Requires 3:1

Large Text AAA

Pass

Requires 4.5:1

Luminance Values

Foreground

0.0000

Background

1.0000

Color Contrast Checker Guide

This tool checks the contrast ratio between text and background colors. It helps designers and developers choose color pairs that are easier to read and more accessible.

How to Use It

  1. Enter or pick the text color.
  2. Enter or pick the background color.
  3. Review the contrast ratio and pass or fail result.
  4. Adjust one color until body text and important UI labels meet the target.

Contrast Targets

WCAG contrast checks compare relative luminance. A common target is 4.5:1 for normal text and 3:1 for large text, though project requirements may be stricter.

Contrast Ratio

(L1 + 0.05) / (L2 + 0.05)

Where:

  • L1= Relative luminance of the lighter color
  • L2= Relative luminance of the darker color

Worked Examples

Body Text

Problem:

Gray text on a white background looks subtle but may be too light.

Solution Steps:

  1. 1Check the foreground and background colors
  2. 2Increase text darkness if the ratio is low
  3. 3Retest after changing the design token

Result:

Readable text helps more users use the page comfortably.

Button Label

Problem:

White text is placed on a bright yellow button.

Solution Steps:

  1. 1Check the ratio
  2. 2Try darker text or a darker button color
  3. 3Keep hover and disabled states readable too

Result:

Interactive controls stay usable across states.

Tips & Best Practices

  • ✓Check hover, focus, active, and error states.
  • ✓Do not rely on color alone to communicate meaning.
  • ✓Use design tokens so accessible colors stay consistent.

Related Calculators

Frequently Asked Questions

No. It is important, but text size, focus states, labels, keyboard support, and layout also matter.
No. Brand colors often need accessible pairings or adjusted shades for text.
Requirements can differ, but disabled controls should still be understandable in context.
Large, bold text is easier to read at lower contrast than small body text.

Sources & References

Last updated: 2026-05-20

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Editorial Note

MyCalcBuddy Editorial Team

This page is maintained as an educational calculator reference.

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Formula Source: Standard Mathematical References

by Various

🔄Last reviewed: May 2026
✓Formula checks are based on standard references and internal QA review.