Notice
Privacy policy
The one-line summary: what you type into the calculator stays in your browser. The only things that leave your device are anonymous visit statistics and whichever advertising cookies you accept.
Updated ·
What we do not collect
There is no signup, no accounts, and we ask for no email, phone or address. We also have no server of our own and no database: the site is a set of static files.
The data you enter in the calculator — your outage hours, your appliances, your budget — is processed entirely in your browser with JavaScript. It is never sent to any server, ours or anyone else’s.
When you use the share button, your parameters travel inside the link you copy. You control that link: if you paste it into a chat, whoever receives it will see those values. We neither store nor see it.
Visit statistics
We use Google Analytics 4 to know how many people visit, from which country, and which pages they read. It informs which guides to write and what to fix.
The configuration sends an anonymised IP address and we do not use it to identify anyone. If you decline measurement cookies, Analytics is not loaded at all.
Google acts as the provider of this service and processes the data under its own policy, which you can review on Google’s privacy page.
Advertising
The site is funded by Google AdSense. Ads appear on every page, including the calculator: that is what keeps the tool free, signup-free and unlimited.
Google and its partners may use cookies to show relevant ads. If you decline advertising cookies, you still see ads, but not personalised ones.
You can control personalisation in your Google account’s ad settings, and block cookies from your browser at any time.
Your consent
The first time you visit we show a notice with two options. Until you choose, no measurement or personalised advertising loads: we use Google’s consent mode with everything denied by default.
Your choice is stored in your browser’s local storage, not in a tracking cookie. To change it, clear the site data in your browser and visit again.
Links and brands
The brands page is informational. We do not sell, do not install, and hold no commercial agreements or affiliate links with any of the brands mentioned. If that changes, it will be declared on that page and here.
Contact
If you want something corrected, if you find an error in the calculations, or if you have a question about this policy, get in touch through the project repository on GitHub.
Results are guiding estimates based on public sizing formulas. They do not replace a design from a certified installer.