Privacy

This worksheet calculates results in your browser. Your selected project, ZIP code, state, quote amounts, and answers are saved in this browser's local storage so you can return later. Quote amounts and answers are not sent to our server by the worksheet. Use “Clear this case” on the main page to remove the saved case from this device.

If you enter a five-digit ZIP code, the site sends that ZIP code to our server, which uses the Zippopotam.us postal lookup to find a city and state. For heating and cooling projects, the server also uses the ZIP center coordinates to request a nearby climate station and its 1991–2020 climate normals from NOAA. NOAA receives a geographic search area, not your quote amounts. No quote amounts are sent with either lookup. You can skip ZIP lookup and choose your state manually. The electricity reference comes from an EIA state-level data snapshot, not a lookup of your address or utility account.

The site currently does not ask for your name, address, email, documents, or account. It loads Google AdSense code; ads may appear after Google approves the site. Google may use cookies or similar technologies for advertising. A Google-certified consent message offers visitors in applicable European regions choices to consent, decline, or manage preferences. See how Google uses information from partner sites. Ordinary hosting infrastructure may also receive technical request data needed to serve pages, such as IP address and browser details.

The site records a small set of first-party product events so we can tell whether the worksheet is useful: opening the calculator, starting a case, reaching a result, reopening a saved case, adding a quote, copying a result, or clearing a case. An event contains the event name, page, selected project category, and a server timestamp. It does not contain quote amounts, answers, ZIP code, city, state, saved-case contents, or a name or email address.

Updated October 2026.