Disclaimer

Last updated: September 2026. Please read this page carefully before using our calculators.

Educational information only

All content on ColorContrast — calculators, articles, tables, and examples — is published for general educational purposes. It is not accessibility advice and is not a substitute for a qualified professional. We are not a full accessibility audit for compliance claimss, and no client or advisory relationship is created by your use of this Site.

Contrast ratios follow WCAG 2.x relative-luminance math exactly — but accessibility is broader than contrast (focus states, color-blindness, motion). A passing ratio is one check, not an audit.

WCAG 3.0 (APCA) proposes a successor algorithm with different thresholds; WCAG 2.x remains the legal standard in most jurisdictions. Verify which standard your project must meet.

Accuracy of calculations

We implement well-known, publicly documented formulas (see the methodology section on each calculator page and WCAG 2.x relative-luminance definitions as applicable). Even correctly implemented formulas produce estimates that depend on your inputs and assumptions. Real-world outcomes vary. Do not rely on a single web tool for a consequential decision.

Advertising disclosure

ColorContrast is funded by display advertising served through Google AdSense. Advertisers have no influence over our content, formulas, or editorial choices, and placement of an ad is not an endorsement.

Errors and corrections

If you spot an error, please email hello@colorcontrast.app with the inputs you used. Verified corrections are published promptly.