Contact
Corrections, calculator requests and questions about the site are all welcome.
Every message is read. Replies are not guaranteed, but reported errors are checked and fixed.
Reporting a wrong result
This is the most useful thing you can send. Please include the calculator page, the values you entered, the result you got and the result you expected — with that, a fix usually takes minutes. Each calculator page shows the formula it uses, so if the formula itself looks wrong, say which part.
Requesting a calculator
Tell us what you need to work out and which inputs you have. Requests that come with a formula or a reference are the quickest to add. It is also worth browsing all calculators first — many are listed under a different name than you might expect.
Privacy
There is no contact form on this site, and nothing you type into a calculator ever leaves your browser. Email is handled by the mail provider only; see the privacy policy.