Privacy

Last updated: 27 October 2026

The calculator

The calculator runs entirely in your browser. The numbers you type are not sent to us or stored on our servers.

Purchases

When you buy, Gumroad processes your payment and shares your name, email address, country and order details with us so we can deliver the product, provide support and handle refunds. We never see your full card details.

Email

We use your email to send your purchase and product updates. If you opt in to other emails, you can unsubscribe at any time from the link in any email.

Analytics

We use Google Tag Manager and Google Analytics to understand how visitors use the site, for example which pages are viewed and whether the calculator is used. These tools may set cookies. We never send the numbers you type into the calculator, or your email address, to analytics.

Your rights

You can ask us to access, correct or delete the personal data we hold about you. Email us.