My EV Tariff Calculator — Are You Charging on the Wrong Tariff?
Time of Use tariffs with cheap overnight rates can make a significant dent in your EV charging costs.
Check my EV tariffWhy EV owners overpay on a standard tariff
Charging an electric car at home adds a large, regular load to your electricity use — often more than everything else in the house combined. On a standard single-rate tariff, every mile you charge is billed at the full day rate, typically around 28p per kWh. That's the most expensive way to run an EV.
EV tariffs work differently. They give you a cheap overnight window — often a third or less of the standard rate — for the hours when your car is sitting on the drive anyway. Because charging is so easy to shift into those hours, EV owners are one of the groups that benefit most from switching. The question is which tariff fits your car, your charger and your mileage, which is what the calculator works out.
Which EV tariffs are worth comparing?
Most major suppliers now offer a tariff built around overnight EV charging. The ones our calculator compares include:
- Intelligent Octopus Go — the most popular EV tariff in the UK. It schedules your charging automatically into a cheap overnight window and often finds extra cheap slots during the day. Needs a compatible car or charger.
- Octopus Go — a simpler version with a fixed overnight cheap window, open to any EV and charger.
- E.ON Next Drive and Next Drive Smart — among the lowest overnight rates available, with a six-hour cheap window.
- EDF GoElectric Overnight — a five-hour overnight cheap window for EV households.
- British Gas Electric Driver and ScottishPower EV Saver — overnight EV tariffs from two of the larger suppliers.
- So Energy and Utility Warehouse also offer competitive overnight EV rates worth checking against the rest.
The cheapest headline rate isn't always the cheapest overall — standing charges, the length of the cheap window and how much you can shift all matter. The calculator compares them against how you actually charge.
How much could you save?
Example: an EV household in London that charges overnight could save around £570 a year by moving from a standard variable tariff to Next Drive Smart.
Illustrative example, updated daily from current rates. Your own saving depends on your car and how you charge — check yours with the calculator.
Not sure which tariff you're on?
If you've never switched since getting your EV, there's a good chance you're charging on a standard tariff and paying far more than you need to. The calculator shows you where you stand and which EV tariff would save you the most.
Common questions about EV tariffs
Do I need a special tariff to charge an EV at home?
You don't have to, but charging on a standard tariff is the most expensive way to run an EV. A dedicated EV tariff gives you a cheap overnight rate for the hours your car is parked, which usually cuts charging costs sharply.
What is the cheapest EV tariff in the UK?
It depends on your car, charger and how much you drive. Intelligent Octopus Go, E.ON Next Drive and Octopus Go are among the most popular, and So Energy and others offer very low overnight rates too. The calculator compares them against your actual charging to find your cheapest option.
Do I need a smart charger for an EV tariff?
Some tariffs, like Intelligent Octopus Go, need a compatible car or charger to schedule charging automatically. Others, like Octopus Go, work with any EV and charger on a fixed overnight window. The calculator takes your setup into account.
How much can an EV tariff save?
Because overnight EV rates can be a third or less of the standard daytime rate, drivers who shift charging into the cheap window often save a substantial amount each year. The calculator gives you a personalised figure based on your own mileage and charging habits.