Privacy Policy

Effective date October 22, 2026. Last updated October 22, 2026.

BuildMath is a static website. We do not run a user database, we do not create accounts, and we do not store your name, email, or project sizes on a server we control. Typing a length into a calculator does not send that number to us.

What stays on your device

The shopping list, if you use it, is saved in your browser’s localStorage. Calculator inputs can appear in the page URL so a job is shareable. Those values never leave your browser unless you send the link to someone, including us.

If you allow ads, we also store a consent choice in localStorage so the banner does not reappear on every page. That value is “granted” or “denied”. It is not a personal profile.

Google AdSense cookies

When ads are turned on, Google AdSense may set cookies to serve and measure ads. We default those cookies to off using Google’s consent mode (ad_storage, ad_user_data, and ad_personalization start as denied). Ads cookies run only after you choose Allow ads. Reject ads cookies keeps them denied. You can change your mind by clearing this site’s data in your browser.

Third-party vendors, including Google, use cookies to serve ads based on a user’s prior visits to this website and other websites. Google’s use of advertising cookies enables it and its partners to serve ads based on visits to this site and other sites on the internet.

You can opt out of personalized ads at adssettings.google.com (opens in a new tab) and through the Digital Advertising Alliance at www.aboutads.info (opens in a new tab). Google’s own explanation of AdSense cookies is in Google’s advertising policies (opens in a new tab). We do not control Google’s servers.

Analytics

BuildMath does not load a separate analytics product such as Google Analytics. If AdSense is on and you allow ads, Google may collect ad measurement data under its own policy. If we add a first-party analytics script later, it will use the same banner and the same denied-by-default consent flags, including analytics_storage.

What we do not collect

We do not ask for a name, address, or payment card. Email you send to hello@buildmathhq.com is ordinary mail. We keep it long enough to answer, then delete it unless we need it to fix a formula. We do not sell lists of visitors because we do not have one.

Children’s privacy

BuildMath is not directed to children under 13. We do not knowingly collect personal information from children under 13. If you believe a child has sent us personal information, email hello@buildmathhq.com and we will delete it.

US state privacy rights

If you live in California or another US state with a privacy law, you may have the right to know what personal information we hold, to delete it, and to opt out of the sale or sharing of personal information. We do not sell personal data. Calculator inputs stay in your browser. If you emailed us, that mail is the only personal data we might have. Email hello@buildmathhq.com to make a request.

Contact

Privacy questions: hello@buildmathhq.com. Related: terms and contact.