Contact

We read everything — especially mistakes.

Whether you've found an error, want a tool built, or just have a question about where a number comes from, here's how to reach us and exactly what to expect when you do.

What you can reach us about

Three good reasons to get in touch

Report an error

Tell us which calculator and what you expected to see. We look into every report against the original source and fix confirmed errors as soon as we can.

Request a calculator

Want one built properly, with a verified formula and a worked example? Send the details. We add tools one at a time, and genuine requests directly shape what comes next.

Ask a question

Curious how a formula works, or why a result looks the way it does? Ask. We're happy to explain our sources and the reasoning behind a number.

The details

How to reach us

Email
support@fastcalc.onlineWe read every message and reply as soon as we can.
Response time
We read everything and try to reply when we can. Confirmed calculator errors are something we prioritise.
What helps us most
For errors: the calculator name, the inputs you used, and the result you expected (with a source if you have one). For requests: what you're trying to work out and who it's for.

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