The short version: the calculators on this site run entirely in your browser. The numbers you type are never sent to us or stored anywhere.
If you sign up for the free starter pack, we collect the email address you give us, so we can send the files and occasional updates. That's the only personal information we ask for. You can unsubscribe from any email with one click, and we'll delete your address on request.
We may use privacy-respecting analytics to count visits and see which tools are useful, and the site may show advertising. Advertising and analytics providers may use cookies as described in their own policies. Some outbound links to business software are affiliate links: if you sign up, the provider may tell us a referral happened and pay us a fee — they do not give us your account details.
Block cookies in your browser if you prefer; every calculator will still work. Questions about this policy: contact details are posted on the About page.
Last updated November 2026.