The cost-per-mile figures for an electric car are striking, but they only land properly when you stretch them across a whole year of driving. Do that and the gap becomes a real sum of money: a few hundred pounds to fuel an EV at home on the right tariff against well over a thousand for a petrol car covering the same miles. The catch is that the tariff swings the answer enormously, so this guide works the annual figures and shows what decides them.
The short answer. At a typical 7,500 miles a year, an electric car charged on an off-peak home tariff costs around 170 pounds in electricity, against roughly 1,080 pounds of petrol for a 50 mpg car. On a standard daytime electricity rate the EV costs about 560 pounds, still well under petrol. Rely on public rapid chargers for everything, though, and the annual cost climbs past the petrol figure. The tariff, not the car, decides where you land.
How the annual sum is built
The arithmetic is simple once you have three numbers: your annual mileage, the car's efficiency in miles per kWh, and your price per unit. Divide the miles by the miles per kWh to get the kilowatt-hours you use in a year, then multiply by your unit rate. The worked figures below use 7,500 miles, close to the average for a UK car, an efficiency of 3.5 miles per kWh, and the same three real rates as the rest of the EV guides: an 8p off-peak EV rate, the 26p standard price-cap rate, and a 79p public rapid rate. The petrol comparison uses a 50 mpg car at 159p a litre. At 3.5 miles per kWh, 7,500 miles needs about 2,140 kWh of electricity over the year.
| How you fuel it | Cost over 7,500 miles | Cost over 12,000 miles |
|---|---|---|
| EV, home off-peak (8p) | ~£170 | ~£275 |
| EV, standard rate (26p) | ~£560 | ~£895 |
| EV, public rapid only (79p) | ~£1,690 | ~£2,710 |
| Petrol car, 50 mpg (£1.59/l) | ~£1,080 | ~£1,735 |
Electricity at 3.5 miles per kWh; petrol at 50 mpg and 159p a litre. Rates checked June 2026: standard rate from the Ofgem price cap for July to September 2026 (26.11p per kWh); off-peak typical of dedicated EV tariffs (broadly 7p to 9p overnight); public rapid average 79p per kWh from the Zapmap price index; petrol at the June 2026 UK average of about 159p a litre. Your own mileage, efficiency and rates will differ.
The off-peak case: a few hundred pounds a year
The headline that makes people switch is in the top row. Fuel an electric car overnight on a dedicated EV tariff and a year of average driving costs less than 200 pounds in electricity. The same miles in a 50 mpg petrol car cost over a thousand, so the EV is roughly six times cheaper to fuel, a saving of the better part of 900 pounds a year that repeats every year you own the car. That is the real prize of home charging, and it rests entirely on getting onto a time-of-use tariff and charging in the cheap window, which the best time to charge guide covers. Without that tariff the saving is far smaller, which is why sorting the tariff is the first thing to do, not the last.
The standard rate: still cheaper, by less
Not everyone can get onto an EV tariff, and charging at the standard price-cap rate tells a gentler version of the same story. At 26p a unit, a year of average driving costs around 560 pounds in electricity, roughly half the petrol figure. So even without the cheap overnight rate, an electric car charged at home is comfortably cheaper to fuel than petrol, just not by the spectacular margin the off-peak row shows. The lesson is that home charging beats petrol either way; the tariff decides whether the win is large or merely solid.
The public-only trap
The bottom EV row is the warning. A driver who cannot charge at home and relies on public rapid chargers for everything pays around 79p a unit, and at that rate a year of average driving costs more than running the petrol car. This is the one situation where an electric car can be dearer to fuel than petrol, and it is worth being honest about it. Public rapid charging is priced for speed and convenience and is a fair deal as an occasional top-up on a long trip, but as the everyday way to fuel a car it throws away the whole running-cost advantage. If you have no way to charge at or near home cheaply, the annual fuel sum is one of the things to weigh carefully before going electric.
Mileage changes the size, not the direction
The second column shows what happens at 12,000 miles a year, a high-mileage driver. Every figure rises, but the ranking holds: off-peak charging is still a few hundred pounds, the standard rate still well under petrol, and public-only still the dearest. In fact the more miles you drive, the bigger the absolute saving from charging cheaply at home, because the per-mile gap is multiplied over more miles. A high-mileage driver who can charge off-peak saves over 1,400 pounds a year against petrol. The headline is the same at any mileage: home off-peak charging wins handsomely, public-only loses, and how far you drive sets the size of the prize rather than who takes it.
Do the sum for yourself
Your own numbers are easy to work out and worth doing, because the averages may not match you. Take your real annual mileage, your car's own efficiency from its dashboard readout, and your actual unit rate, and run them through the same two steps: miles divided by miles per kWh gives your yearly kWh, times your rate gives your annual cost. The running cost calculator handles the same kind of sum, and the cost of charging at home guide has the per-charge and per-mile detail behind these annual totals. Whatever the exact figures, the shape is reliable: charge at home in the cheap hours and a year of motoring costs a fraction of the petrol equivalent.
The bottom line
Over a typical year an electric car charged on an off-peak home tariff costs around 170 pounds to fuel, against roughly 1,080 pounds of petrol, a saving near 900 pounds that returns every year. On a standard rate the EV still costs about half what petrol does. Only relying on public rapid chargers for everything flips the result, pushing the annual cost above petrol. Higher mileage widens the saving rather than narrowing it. The tariff is the decisive number, so charge at home, in the cheap window, and a year of driving costs a fraction of what the pump would take.