About this site & where the numbers come from
Figures last checked:
Electricity prices
Standard variable rate is the Ofgem energy price cap national average unit rate for electricity, Direct Debit customers. Off-peak EV tariff rate is illustrative of typical dedicated EV/overnight tariffs (e.g. Intelligent Octopus Go-style products), which vary by supplier, region and whether VAT/standing charges are included. Always check your own tariff — the calculators let you enter a custom rate for this reason.
Petrol & diesel prices
UK average pump prices, checked periodically against published fuel price trackers.
EV battery size & efficiency
Usable battery capacities and real-world miles-per-kWh figures are typical averages for each model/trim, gathered from manufacturer specifications and real-world UK driving data. Individual cars vary with wheel size, options, weather, and driving style — treat these as a sensible starting point, not an exact figure for your specific car.
How this site is maintained
This is a small, independent set of calculators. Pricing figures are reviewed roughly every quarter (in step with Ofgem's price cap changes). If you spot a figure that's clearly out of date, or a car that's missing, let us know.
What this site isn't
This site is not affiliated with, endorsed by, or operated on behalf of any energy supplier, EV manufacturer, or Ofgem. All figures are estimates for general guidance and shouldn't be treated as a substitute for your own bill or a manufacturer's official specifications.