EV Charging Cost Per Mile Calculator
Work out exactly how much each mile costs in your electric car. Enter your efficiency and charging mix to see cost per mile, cost per 100 miles, and estimated annual cost.
Reviewed by Richard Ross · Last updated April 2026
How EV Charging Cost Per Mile Calculator works
What cost per mile actually measures
Cost per mile is the simplest direct comparison between an electric car and a petrol or diesel equivalent — it strips out finance, insurance, and depreciation and shows only the energy cost to move the car one mile. For an EV, the formula is electricity tariff (pence per kWh) divided by the car's efficiency in miles per kWh. The calculation looks straightforward, but in practice the two inputs are highly variable: home electricity tariffs differ from public rapid charging by a factor of three or more, and real-world efficiency depends on temperature, speed, terrain, and load. This calculator handles the variability by blending a home rate and a public rate weighted by how much of your charging you do at each, so the figure reflects how you actually use the car.
How the blended tariff calculation works
The calculator computes a weighted average electricity cost using your home charging percentage and public charging percentage as weights. If 80% of your charging is at home at 24p/kWh and 20% is at public rapid chargers at 65p/kWh, the blended rate is (0.80 x 24) + (0.20 x 65) = 32.2p/kWh. That blended rate is then divided by your miles per kWh to produce the cost per mile, and multiplied through to give cost per 100 miles and annual cost at 10,000 miles. The blend matters: every 10 percentage points you shift from home charging to public charging adds roughly 4p to the blended rate at current tariffs, which is around 1.2p per mile at 3.5 miles per kWh efficiency.
Worked example: a Tesla Model 3 doing 12,000 miles a year
Take a Tesla Model 3 Standard Range with a real-world efficiency of 4.0 miles per kWh. The driver charges 90% at home on the Ofgem 24p/kWh price cap and 10% at a public rapid charger at 70p/kWh. Blended rate: (0.90 x 24) + (0.10 x 70) = 28.6p/kWh. Cost per mile: 28.6 / 4.0 = 7.15p. Annual cost at 12,000 miles: 12,000 x 7.15p = £858. If the same driver moved to an Octopus Go-style overnight tariff at 7.5p/kWh for home charging, the home portion drops to 1.9p per mile and the blended figure falls to roughly 3.4p per mile — annual cost of around £408. The £450 a year difference is what makes EV-specific tariffs so important to the running-cost case.
EV cost per mile vs petrol cost per mile
A petrol car at 40 MPG and a UK pump price of 140p per litre costs approximately 140 / (40 / 4.546) = 15.9p per mile. A diesel at 50 MPG and 147p per litre costs about 13.4p per mile. By comparison, a typical EV charged predominantly at home falls in the 5-9p per mile range, dropping to 2-3p per mile on a dedicated overnight tariff. Pure public rapid charging at 65-85p/kWh, however, can push EV cost per mile to 18-24p — more expensive than petrol. The headline "EVs cost half as much per mile" claim only holds for drivers with off-street parking and a home charger. Drivers who rely on public charging need to budget very differently. These are estimates; your actual costs depend on your tariff, your car's efficiency, and your charging mix.
Why real-world efficiency differs from WLTP
Manufacturers publish miles per kWh figures derived from the WLTP test cycle, which is conducted under controlled lab conditions. Real-world efficiency is usually 15-25% lower. Motorway driving at 70mph cuts efficiency by around 20-30% versus mixed driving because aerodynamic drag rises with the square of speed. Cold weather below 5C reduces efficiency by 20-30% due to battery heating losses and cabin heating draw — though heat pumps fitted to most newer EVs cut that figure roughly in half. Roof boxes, towing, and a heavy load all reduce efficiency further. The pragmatic figure to use in this calculator is your in-car average display reading over the last few thousand miles, not the manufacturer's spec sheet number.
What is not included in cost per mile
Cost per mile as calculated here captures only the energy cost of charging. It excludes battery degradation (which slowly reduces miles per kWh over years), charge losses at the wall (typically 5-10% lost between meter and battery), tyre wear (EVs wear tyres roughly 20% faster than equivalent petrol cars due to weight and torque), and any standing charge on your electricity bill. For a more complete total cost of ownership comparison, see the EV vs petrol running costs calculator linked below. The cost per mile figure is the cleanest input for that wider calculation, but it should not be confused with total cost to own.
Related guides
For a fuller comparison of EV and petrol total running costs, see the dedicated calculator.
Compare EV vs petrol total running costs →Frequently asked questions
How much does it cost per mile to run an electric car in the UK?
At typical 2026 electricity rates, an EV costs around 5-8p per mile when charged mainly at home. This compares favourably with petrol cars at 15-20p per mile. The exact figure depends on your electricity tariff and how efficient your car is.
What is a good miles per kWh for an EV?
Most modern EVs achieve between 3 and 4.5 miles per kWh in real-world driving. Smaller, more efficient cars like the MG4 can achieve 4+ miles per kWh, while larger SUVs and performance EVs may only get 2.5-3 miles per kWh.
How does EV cost per mile compare to petrol?
An EV charged at home costs roughly 5-8p per mile, while a petrol car averaging 40 MPG costs around 16-18p per mile at current fuel prices. That makes an EV about 60-70% cheaper per mile to run.
Does cold weather increase EV running costs?
Yes. In cold weather (below 5 degrees C), EV efficiency drops by around 20-30% due to battery heating and cabin heating. This increases the cost per mile proportionally. Using a heat pump (fitted to most newer EVs) reduces this impact.
How do I calculate the cost per mile for my electric car?
Take your electricity tariff in pence per kWh and divide by your car's efficiency in miles per kWh. At the Ofgem Q1 2026 price cap of 24p/kWh and an efficiency of 3.5 miles per kWh, that is 24 / 3.5 = 6.9p per mile. If you split charging between home and public chargers, calculate a weighted blended rate first — for example, 80% home at 24p plus 20% public at 65p gives a blended 32.2p/kWh, or about 9.2p per mile at the same efficiency. This is an estimate; your actual cost depends on your tariff and real-world efficiency.
What is the cheapest way to charge an electric car at home in the UK?
An EV-specific time-of-use tariff is almost always cheapest. Octopus Go and similar overnight tariffs offer roughly 7.5p/kWh for around five hours overnight in 2026, compared with the 24p/kWh Ofgem price cap on standard tariffs. At 7.5p/kWh and 3.5 miles per kWh, off-peak charging costs around 2.1p per mile — about a third of standard-rate home charging and roughly an eighth of public rapid charging.
Is an electric car really cheaper per mile than petrol?
For drivers who charge mostly at home, yes. At UK petrol prices of around 140p per litre and 40 MPG, a petrol car costs approximately 15.9p per mile. An EV charged at the 24p/kWh price cap costs around 6.9p per mile — less than half. The gap closes if you rely on public rapid charging at 65-85p/kWh, where cost per mile can match or exceed an efficient petrol car. This is an estimate; your actual cost depends on tariff, driving style, and how often you use public chargers.
Does battery degradation affect cost per mile over time?
Yes, indirectly. Most modern EV batteries lose around 1-2% of capacity per year on average, which slightly reduces miles per kWh and therefore increases cost per mile. After 8 years, a battery at 85-90% of original capacity will cost roughly 10-15% more per mile than when new at the same tariff. Manufacturer battery warranties typically guarantee 70% capacity at 8 years or 100,000 miles.
These calculations are estimates based on 2026/27 HMRC and DVLA rates. Speak to a lender or qualified financial adviser for a personalised quote.