Legal

Privacy Policy

We don't require accounts, we don't sell data, and we keep it simple.

Last updated: May 11, 2026

WattMath is a free, anonymous tool. We do not require account creation, and we do not collect personally identifiable information through our calculators.

Analytics

We use Google Analytics 4 (GA4) to understand aggregate traffic patterns — which calculators are most used, where our visitors come from, and how the site performs. GA4 collects anonymized usage data such as page views, session duration, and general geographic region (country/state level). We do not enable Google Signals or any cross-device tracking feature.

You can opt out of Google Analytics tracking at any time by installing the Google Analytics Opt-out Browser Add-on .

Calculator Inputs

When you use a WattMath calculator, your inputs (ZIP code, monthly bill, vehicle information, etc.) are processed in your browser and sent to our backend API solely to retrieve solar production data and electricity rates. We do not store, log, or associate your inputs with any identifier.

Cookies

WattMath itself does not set first-party cookies. Two categories of third-party cookies may be placed during your visit:

  • Analytics cookies — Google Analytics 4 sets cookies to measure aggregate traffic patterns. These do not identify you personally. You can opt out via the Google Analytics Opt-out Browser Add-on .
  • Affiliate attribution cookies — When you click an affiliate link on WattMath (for example, an EV charger product link or a solar quote CTA), the affiliate network — currently Amazon Associates, and potentially CJ Affiliate or Impact for solar and HVAC partners — places a cookie on your device. This cookie attributes any qualifying purchase or quote request to WattMath within the network's attribution window (typically 7 to 90 days, varying by partner). We do not receive your personal information through these cookies; the network reports only aggregate conversion data to us.

We do not use session cookies, login cookies, or persistent cookies for our own purposes.

Third-Party Data

We do not sell, rent, or share your data with any third party for commercial purposes. Third-party services that may receive data about your visit are:

  • Google Analytics 4 — aggregate traffic and usage data on every page.
  • Google AdSense and its advertising partners — serve display ads and may set cookies, including the DoubleClick / DART cookie, to personalize what you see. See the Display Advertising section below.
  • Affiliate networks (Amazon Associates, CJ Affiliate, Impact) — receive a click event and set an attribution cookie only when you click an affiliate link. They do not receive data about pages you visit on WattMath where no affiliate link was clicked.

Display Advertising

WattMath uses Google AdSense to serve display advertisements that help fund the calculators and keep them free to use. As part of AdSense, third-party vendors — including Google — use cookies to serve ads based on a user's prior visits to this website or other websites. Google's use of advertising cookies, including the DoubleClick DART cookie, enables it and its partners to show ads to our visitors based on their visits to WattMath and other sites on the internet.

You can opt out of personalized advertising by visiting Google Ads Settings . You can also opt out of a third-party vendor's use of cookies for personalized advertising by visiting www.aboutads.info . For more information on how Google uses data when you use partner sites or apps, see policies.google.com/technologies/partner-sites .

Opting out of personalized ads does not stop ads from being shown — it only prevents them from being tailored to your browsing history.

Affiliate Links

Some calculator pages contain affiliate links. WattMath currently participates in the Amazon Associates program and may add solar, HVAC, and EV charging affiliate programs over time. Clicking an affiliate link does not increase the price you pay; the partner pays any commission from their marketing budget.

We display a disclosure notice on every page that contains affiliate links, placed before the relevant call-to-action. For full details on how our affiliate relationships work and which networks we use, see our Affiliate Disclosure page.

Contact

Questions about this policy? Email us at [email protected].