Privacy policy
Short version: the calculators run in your browser, your inputs never reach us, and there are no accounts, no forms, and no user database anywhere on this site.
What runs on these pages
All calculator math executes locally in your browser. Our host (Cloudflare) collects aggregate, cookie-free analytics (page views, country, browser family) that cannot follow you across sites. Infrastructure-level server logs (IP address, user agent, timestamp) exist briefly, as they do for every site on the internet.
The record we keep ourselves
A visit total cannot show whether the panel math was any use, so the site keeps a narrow record of its own: a page loaded, a field changed, a copy, a print, a click out to a retailer or a quote service, a click out to anywhere else. For each one: the page path, which event it was, the country the request came from, the date, and the referring site's host name. That is the whole record. Not a cookie, not an identifier carried from page to page, not your IP address, and not the kilowatt-hour figures or roof details you enter. Browsers sending Do Not Track or Global Privacy Control are skipped.
Advertising
Where advertising appears it is served by Google AdSense, which may use cookies or device identifiers under Google's own policies, with consent mechanisms where law requires them. Referral links, where present, set their cookie on the destination site, not here, and are marked sponsored.
Write to the contact address and we keep the thread as long as it is useful and share it with nobody.
Questions: same address. Effective 2026-07-15.