Terms of use
Using means accepting what is below. It is short on purpose.
Last updated 21 August 2026.
Use the answers freely
The results this site calculates are yours. Put them in your homework, your report, your quote, your drawing set. There is no attribution requirement on a number, and there could not sensibly be one: the site did not invent the Pythagorean theorem, and neither did I.
The writing is a different matter. The learning zones, the worked examples, the unit definitions and the illustrations are original work and are copyright. Quote a passage with credit and a link, by all means. Republishing the material wholesale, or scraping the site to rebuild it somewhere else, is not on.
What the site promises
That it tries very hard to be right, and shows you enough of its working that you can check. Every solver is tested against answers worked out by hand rather than against numbers the code produced, sources are named, and constants say whether they are exact by definition or measured. The Guide explains how all of that works and where the limits are.
What it does not promise is that it is right for your case. A formula can be correct and still be the wrong formula for the problem in front of you, a correlation can be outside the range it was fitted to, and a real system has conditions no page can know about. The site is for education. If a number matters commercially or to somebody dependent on it, reproduce the calculation yourself before you rely on it.
Not professional advice
Nothing here is engineering, medical, financial or legal advice, and using the site does not create a professional relationship of any kind. Work that requires a licensed professional still requires one. That applies with particular force to anything structural, anything pressurised, anything electrical, and anything with a dose in it.
Where responsibility sits
The site stands behind its math and is not responsible for how the results are used. To the extent the law allows, it is provided as it is, without warranty, and I am not liable for loss arising from its use. That is the same sentence as the footer, said once more with the legal edges on.
Availability, links and changes
The site may be unavailable, may change, and may drop or alter any page without notice. It links to outside sites and carries advertising, and I am not responsible for what sits on the other end of a link I do not control. See the privacy page for what the advertising does.
These terms may change; the date at the top moves when they do. They are governed by the laws of British Columbia, Canada. If something here is unclear or seems wrong, the contact page is the way to say so.