We work hard to keep every calculator and guide on this site correct, and we fix verified mistakes promptly. This page is our public corrections log: every error we find or that a reader reports, what was wrong, and what we changed.
How to Report an Error
If you find a wrong answer, a misleading explanation or a broken calculator, please tell us through the Contact page. Include the page you were on, the numbers you entered, the answer you got, and the answer you expected. We check every report against our formulas (see Methodology) and reply when a fix is published.
Corrections Log
15 November 2026 — Site launch. No corrections yet. All thirteen calculators were tested with known answers before launch, including 3/4 = x/20 → x = 15 and the true proportion 7/8 = 14/16 with cross products 112 = 112.
When a correction is made, it will be listed here with the date, the page affected, the error, and the fix. We do not silently change results: if a calculator answer changes, this log says so.
Our Accuracy Promise
We check formulas against standard textbooks, test calculators with known answers, and show our working on every tool page so you can verify results yourself. If a result looks wrong, trust your working, check it with the cross-product test on the Proportion Calculator, and let us know.