Contact

The fastest way to reach us is email:

[email protected]

We read everything — bug reports, feature requests, tool suggestions, and corrections to math or reference data are all welcome. Replies usually within a few days.

Found a bug?

Source code is on GitHub. Open an issue with the page URL, what you entered, what you expected, and what you got. Screenshots help.

Looking for a tool we don't have?

Email or open a GitHub issue. We prioritize tools that get high search volume and have authoritative source data we can cite (when applicable).

What to include

If you are reporting a bug, include the exact page URL, your browser, the input that produced the issue, and the result you expected. If the issue involves a calculator or converter, include the units, dates, rates, or assumptions you used so we can reproduce the same result.

If you are suggesting a new tool, describe the job it should help with, who would use it, and what a correct result looks like. We prefer focused tools with transparent behavior over broad tools that hide important assumptions.

Privacy note

Please do not send passwords, private keys, bank records, tax documents, customer data, or other sensitive personal information. If a screenshot is useful, redact anything private before sharing it in email or GitHub.