Terms of Use

Use of the calculators

The calculators on this site are free to use for any purpose, including schoolwork and commercial work. No account is required and there is no usage limit.

You are welcome to link to any page here. If a calculator or guide is useful to your readers, a link is appreciated but not required.

Accuracy

The calculators are tested against known results, and the step-by-step working is shown precisely so that you can check it rather than take it on trust.

That said, they are provided as-is and without warranty. For work where an error would matter — engineering, finance, anything graded — verify the result independently. Responsibility for how a result is used rests with you.

The apps

The mobile apps are licensed through the App Store and Google Play under their standard terms. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period, and can be managed or cancelled at any time from your Apple or Google account settings.

Changes

These terms may be updated as the site changes. The current version is always the one on this page.