Contact

Reporting a wrong result

This is the most useful thing you can send, and it gets priority over everything else. To make it actionable, include:

• the address of the calculator page,
• the values you entered,
• the result you got and the result you expected,
• and, if you have one, the source that supports your figure — a statute, a clinical reference, a bank's own schedule.

A fix usually ships within a few days of a confirmed report, and the page's revision date is updated when it does.

Suggesting a calculator

Requests are welcome, particularly for calculations you currently do by hand or in a spreadsheet. Describe the calculation and what you would use it for; that context decides whether a tool is worth building better than a bare formula would.

Translation and wording

The site exists in six languages and is written by someone who is native in one of them. Stiff phrasing, a wrong term of art, or a passage that reads as translated rather than written — all worth reporting, and quick to fix.

Privacy, legal and takedown

Data-protection questions, copyright complaints and takedown requests go to the same address and are answered in writing. See the privacy policy for what is and is not collected before writing — the answer to most privacy questions is that nothing you typed was ever stored.

Response time

This is not a staffed support desk. A reply typically takes a few days, longer over holidays. Every message is read, including the ones that only say a number looks off.