Privacy & storage
What happens to the information you enter and what may be processed when you visit the site.
Last updated: 23 July 2026
Who is responsible for this site?
myevnumbers is an independently operated calculator. The site operator is responsible for the calculator content and for keeping this notice accurate. A public privacy contact address has not yet been added; this should be supplied before the site is promoted more widely.
Calculator entries
Values entered into the calculators—such as battery size, charge level, mileage, electricity prices and charging speed—are processed by JavaScript in your browser. The calculator does not send these values to the site operator or store them in an application database.
Optional EV and tariff profile
The My EV & Tariff page can save the following on your device: vehicle name, usable battery capacity, efficiency, maximum AC and DC charging rates, home/public/cheap electricity prices, and cheap-rate start and end times.
This uses browser local storage under the key myevnumbers-profile. It exists only to provide the saved-profile feature you request. It remains until you reset the profile, clear this site’s data in your browser, or remove it through browser settings. It is not used for tracking and is not shared with the site operator. Existing profiles saved by an earlier version of the calculator are migrated automatically.
Hosting and technical logs
The current site is hosted using ChatGPT Sites, an OpenAI service. Like most hosting services, the provider may process routine technical information such as IP address, browser type and settings, requested pages, and request date and time to deliver, protect and operate the service. This information is handled by the hosting provider under its own privacy terms; it is not combined with your calculator entries by this app.
See OpenAI’s privacy policy for its purposes, retention approach, international processing and privacy-contact details. If myevnumbers moves to another host, this section must be updated before that version goes live.
Google Analytics and your choice
If you select Allow analytics, the site loads Google Analytics using measurement ID G-SPB9T17FRM. Google may then process information such as pages viewed, approximate location derived from an IP address, device and browser details, and visit timing. We use this information to understand which calculators are useful and improve the site.
Google Analytics does not receive the figures you enter into the calculators or the EV and tariff profile stored in your browser. Analytics is off by default and its script is not loaded unless you allow it. You can change your decision at any time using Analytics choices in the footer. Declining does not affect any calculator.
For more about Google’s handling of Analytics data, see Google’s Privacy Policy.
Cookies and similar technologies
The site uses local storage for the optional EV profile and to remember whether you accepted or declined analytics. The saved-profile storage provides a feature you request. The analytics choice prevents the site from repeatedly asking and records no preference other than accepted or declined. Google Analytics may use cookies or similar technologies only after you allow it. The site does not use advertising cookies.
Your choices and rights
- Use every calculator without saving a profile.
- Remove the saved profile with Reset defaults on the profile page or clear this site’s data in your browser.
- For hosting information handled by OpenAI, use the rights and contact routes in OpenAI’s privacy policy.
- If you are unhappy with how personal information is handled, you may complain to the UK Information Commissioner’s Office (ICO).
Changes to this notice
This page will be updated if the site adds analytics, advertising, accounts, forms, a database, a different hosting provider or another feature that changes how information is handled.