Corrections and feedback

Accuracy is the point of this site, so error reports get priority over new features.

Report a problem

Use the contact form and choose “Report an error”. The most useful reports include the calculator, the values you entered, the result you got and what you expected — with a source if you have one. Each calculator page has a direct link that fills in which calculator you mean.

What happens next

1. We reproduce the issue with your inputs.
2. If the result is wrong, we fix the calculation or the description, add a regression test so it cannot recur, and bump the calculator’s version number.
3. If the calculation is correct but the page was unclear, we rewrite the explanation.
4. Material corrections are noted on the calculator page with the date.

If you leave an email address, we will tell you the outcome. We do not publish your name or details.