Short answer
An electric car is usually cheaper to run if you can charge mostly at home, drive enough miles each year, and avoid paying too much for the car in the first place. It is not automatically cheaper if you rely on public rapid charging, pay high insurance, or lose a lot through depreciation.
Home-charged EVs often win on energy cost. Public-charged EVs can be much closer to petrol or diesel. Full ownership cost depends on mileage, purchase price, finance, insurance, tax, tyres and resale value.
Check the charging maths first
Estimate charge cost, miles added and cost per mile using your own battery size, tariff and efficiency.
EV cost per mile compared with petrol and diesel
The biggest running-cost advantage of an electric car is the energy cost per mile. The table below uses recent UK pump-price averages and published electricity-rate assumptions, but you should replace them with your own prices before making a decision.
| Vehicle / charging type | Example efficiency | Price assumption | Approx. cost per mile | 10,000 miles/year |
|---|---|---|---|---|
| Petrol car | 40 MPG | 155.54p/litre | 17.7p | £1,768 |
| Diesel car | 50 MPG | 176.71p/litre | 16.1p | £1,607 |
| EV charged at home | 3.5 miles/kWh | 26.11p/kWh | 7.5p | £746 |
| EV using public charging | 3.5 miles/kWh | 54p/kWh | 15.4p | £1,543 |
On these assumptions, the home-charged EV has a clear energy-cost advantage. The public-charged EV is still cheaper than the petrol example, but it is much closer to diesel. That is why charging access matters so much.
Charging access is the deciding factor
If you have off-street parking and can charge at home, an EV can be very cheap per mile. If you cannot charge at home, you may depend more on workplace, supermarket, destination or rapid public chargers, and the cost advantage can shrink quickly.
A dedicated EV tariff can change the result because some tariffs make overnight charging much cheaper than the standard unit rate.
EV tax is no longer automatically zero
Older advice often says electric cars pay no car tax. That is no longer a safe assumption. From April 2025, electric, zero and low emission cars were brought into vehicle excise duty.
| EV registration period | VED treatment | Why it matters |
|---|---|---|
| Registered on or after 1 April 2025 | £10 first year, then standard rate | New EVs still have a tax line in the running-cost calculation. |
| Registered 1 April 2017 to 31 March 2025 | Standard rate | Many used EVs now have the same standard-rate issue. |
| Registered 1 March 2001 to 31 March 2017 | Lower standard rate | Older EVs may still be cheaper on VED, but they are not common choices for everyone. |
Tax is usually not the biggest EV cost, but it is a good example of why old “EVs are free to run” claims can be misleading.
Insurance, servicing and tyres can change the answer
EVs can be cheaper to service because there are fewer oil, exhaust and engine-related items. But that does not mean every maintenance bill is lower. Tyres can wear faster on some EVs because of vehicle weight and instant torque, and insurance can be higher for some models.
The practical comparison is not “electric versus petrol” in general. It is one real EV against one real petrol or diesel alternative, with quotes and estimates for your postcode, mileage and driving history.
Depreciation and purchase price matter more than people think
Fuel savings are often measured in hundreds of pounds per year. Purchase-price differences and resale-value changes can be measured in thousands. That is why the cheapest car to run is not always the car with the cheapest energy cost.
For example, saving £900 a year on energy is powerful. But if the EV costs £5,000 more to buy and loses value faster over your ownership period, the overall saving may take years to appear.
Compare ownership loss
Estimate how much value a car could lose over your ownership period.
The mileage test: when EV savings become meaningful
The more miles you drive, the more energy-cost differences matter. Low-mileage drivers may not save enough on charging to justify a more expensive car. High-mileage drivers who charge mostly at home can see the benefit much sooner.
annual energy saving = petrol or diesel annual fuel cost - EV annual charging costUsing the examples above, a home-charged EV at 10,000 miles could cost about £746 in electricity, compared with about £1,768 for the petrol example. That is roughly £1,022 a year before considering purchase price, insurance, maintenance and depreciation.
Use the fuel cost calculator to compare your own MPG, miles per kWh and local prices.
Company cars and business mileage need separate treatment
For company-car or employer reimbursement situations, do not just use household energy prices. GOV.UK publishes advisory fuel rates and advisory electric rates, including separate electric rates for home and public charging.
From 1 June 2026, the advisory electric rates for fully electric cars are 7p per mile for home charging and 15p per mile for public charging. The published table also shows a weighted EV efficiency assumption of 3.59 miles per kWh.
Claiming business miles?
Estimate approved mileage amounts and possible tax-relief shortfalls.
When an EV is likely to be cheaper
- You can charge mostly at home.
- You drive enough miles for energy savings to matter.
- You buy at a sensible price, especially used.
- Your insurance quotes are not much higher than petrol or diesel alternatives.
- You plan to keep the car long enough to benefit from lower running costs.
- You have realistic expectations about public charging on long journeys.
When an EV may not be cheaper
- You cannot charge at home and often use expensive public rapid chargers.
- You do very low annual mileage.
- The EV costs much more to buy or finance than your alternative.
- Insurance is significantly higher.
- You change cars quickly and take the biggest depreciation hit.
- You need a car for long rural journeys where charging access is awkward.
The right answer is not ideological. It is arithmetic. Compare the specific cars, the specific mileage and the specific charging pattern.
FAQs
Is an electric car cheaper per mile than petrol?
Usually yes when charged at home. On the example figures used here, home charging is roughly 7.5p per mile, while a 40 MPG petrol car is roughly 17.7p per mile.
Is an electric car cheaper if I use public charging?
Not always. Public charging can make an EV much closer to petrol or diesel on energy cost, especially if you rely on rapid chargers rather than home or workplace charging.
Do electric cars pay road tax in the UK?
Yes, many EVs now do. From April 2025, electric, zero and low emission cars were brought into VED, with different treatment depending on registration date.
Do EVs cost less to service?
They can, because they have fewer engine-related service items. But tyres, insurance, repairs and warranty terms still need checking for the specific car.
What is the biggest hidden EV cost?
Depreciation can be the biggest hidden cost. Energy savings can be wiped out if the purchase price is high or the car loses value faster than expected.
Figures and sources to check
The examples on this page are estimates and should be updated when fuel prices, electricity prices, tax rules or advisory rates change.
- UK Fuel Price Index — weekly average petrol and diesel prices.
- Ofgem price cap unit rates — electricity unit-rate assumptions by payment method and period.
- GOV.UK advisory fuel rates — company-car fuel and electric advisory rates.
- GOV.UK electric vehicle tax guidance — VED treatment for electric, zero and low emission vehicles.