Contact

Found an error, or need a calculator that is not here yet? Your feedback directly shapes what gets built next.

This website has no contact form. Clicking the address opens your own email program; nothing is sent until you press send there. If the link does not open anything, copy the address into your email app.

Reporting a calculation error

Accuracy matters more than anything else on this site. If you think a result is wrong, please include:

• the calculator name, or the page link — use the Copy link button under the result, which saves your inputs;
• the result you expected, and how you worked it out or where it comes from (a standard, a textbook or a manufacturer’s table).

Suggesting a calculator

Tell us what you are trying to calculate, the formula or standard you normally use, and the units you work in. Requests that many people need are built first.

Business and other inquiries

For collaboration, education partnerships or other questions, use the same email address.

We cannot provide engineering design, approval or certification services.