Terms of Use

Acceptable use

You may use the calculators for personal and commercial purposes, including embedding them in your own analysis. You may not scrape the site at a rate that interferes with other users, attempt to bypass any access controls, or use it to train models that compete with the site.

You agree not to submit content that is unlawful, infringing, or harmful through any input fields or contact form.

Intellectual property

The site text, calculators, design and source code are owned by us or our licensors. The math itself is generally not copyrightable, but the explanatory text, illustrations and engine implementations are.

No warranties

The site is provided “as is” without warranties of any kind, express or implied. We try to keep calculators correct and up-to-date but cannot guarantee the absence of bugs. Always cross-check results that drive important decisions.

Limitation of liability

To the maximum extent permitted by law, we are not liable for any indirect or consequential loss arising from use of the site. Our total liability for any direct claim is limited to the amount you paid us in the twelve months before the claim — which is zero, because the site is free.

Changes

We may update these terms occasionally. Material changes will be flagged on the homepage. Continued use after a change indicates acceptance of the new terms.