EV vs Petrol & Diesel Running Costs Calculator
Charging at home on an off-peak tariff costs about 2.3p per mile. Petrol costs about 18.9p per mile. Public rapid charging costs about 23.9p per mile — more than petrol. Put your own numbers in below.
Energy costs only — excludes insurance, servicing, tyres, depreciation and the electricity standing charge. Estimates based on the figures you enter.
32A Single Phase 7.4kW Smart EV Wall Charger — Type 2, App & RFID
The cheap rate only helps if your car can actually refill inside the off-peak window. A 3-pin plug manages about 2.3kW — nowhere near enough, so you end up finishing the charge at the full daytime rate. This unit delivers 7.4kW, roughly three times as much, which fills most cars overnight well inside the window.
- 7.4kW, 32A — adds 25–30 miles of range per hour
- App & scheduling — set it to charge only during your off-peak hours
- RFID access — control who can use it
- IP66 weatherproof, CE certified to EN 62752 by TUV
EV, petrol and diesel cost per mile compared
Based on the default prices below. These are the same figures the calculator starts with.
| How you fuel it | Cost per mile | Cost per 10,000 miles | Assumed price | Assumed efficiency |
|---|---|---|---|---|
| Electric — home, off-peak tariff | 2.3p | £227 | 7.5p per kWh | 3.3 miles per kWh |
| Electric — home, standard rate | 8.0p | £798 | 26.32p per kWh | 3.3 miles per kWh |
| Petrol car | 18.9p | £1,887 | 174.3p per litre | 42 mpg |
| Diesel car | 19.3p | £1,929 | 199.4p per litre | 47 mpg |
| Electric — public rapid charging | 23.9p | £2,394 | 79p per kWh | 3.3 miles per kWh |
Electricity: Ofgem price cap, 1 October to 31 December 2026 (26.32p per kWh, direct debit, England, Scotland and Wales). Fuel: UK pump averages, week ending 12 October 2026. Public charging: Zapmap index for 50kW and above. Off-peak rate is illustrative of dedicated EV tariffs and varies by supplier.
Is it cheaper to charge an electric car at home or at a public charger?
Charging at home is far cheaper. On an off-peak EV tariff at around 7.5p per kWh, an electric car costs roughly 2.3p per mile. On a public rapid charger at around 79p per kWh, the same car costs roughly 23.9p per mile — more than running a petrol car, which works out at about 18.9p per mile at current pump prices.
That gap is the single most important fact about EV running costs, and it is the reason a home charge point matters. An electric car is only cheap to run if you can charge it at home.
How much does it cost to charge an electric car at home?
Multiply your battery size by your electricity rate. A 60kWh battery charged from empty costs about £15.79 at the Ofgem capped rate of 26.32p per kWh, or about £4.50 on an off-peak EV tariff at 7.5p per kWh.
In practice you rarely charge from empty, so a typical overnight top-up costs a few pounds. A 7.4kW wall charger adds roughly 25 to 30 miles of range per hour, so most cars fill up comfortably inside a single off-peak window.
How much can you save switching from petrol to electric?
At 10,000 miles a year, a 42mpg petrol car costs around £1,887 in fuel. The same mileage in an electric car costs around £798 on a standard home tariff, or around £227 on an off-peak EV tariff.
Those are energy costs only. They exclude insurance, servicing, tyres and depreciation, which differ between vehicles and are not what this page is comparing.
Why is off-peak EV charging so much cheaper?
Electricity demand collapses overnight, so suppliers sell it cheaply to anyone who can shift their usage into those hours. Dedicated EV tariffs offer a window of several hours — typically somewhere between 11pm and 6am — at a fraction of the standard rate.
A car plugged in on a timer uses that window without you doing anything. It is the same electricity; you are simply buying it when nobody else wants it.
Do you need a home wall charger to get the cheap rate?
In practice, yes. Most off-peak EV tariffs expect a compatible smart charge point, and some require one to qualify. A standard 3-pin plug is limited to about 2.3kW, which is too slow to refill a car inside a short off-peak window — you would still be charging at full price in the morning.
A 7.4kW wall charger pulls roughly three times as much, so an overnight top-up finishes while the cheap rate is still running. That is the difference between 2.3p a mile and 8p a mile.
What changes your real running costs?
- Winter. Expect 20–30% worse efficiency in cold weather. Heating the cabin draws from the same battery.
- Speed. Motorway driving is harder on an EV than town driving — the opposite of a petrol car.
- Your tariff. The single biggest variable. The gap between an off-peak EV rate and the standard cap is more than three to one.
- How often you charge away from home. Occasional rapid charging on long trips barely moves the average. Relying on it entirely wipes out the saving.
- Your actual mpg. Manufacturer figures are optimistic. Use what your car really returns.
Where these figures come from
Electricity is Ofgem's price cap for 1 October to 31 December 2026: 26.32p per kWh for direct debit customers in England, Scotland and Wales. Petrol and diesel are UK pump averages for the week ending 12 October 2026: 174.3p and 199.4p per litre. Public charging is Zapmap's index for 50kW and above: around 79p per kWh.
The off-peak rate of 7.5p per kWh is illustrative of dedicated EV tariffs. Eligibility and rates vary by supplier, and some require a compatible smart charger. Every figure on this page is an estimate — change the inputs in the calculator to match what you actually pay.
Getting the cheap rate needs a home charger
A 3-pin plug tops out at about 2.3kW — too slow to fill a car inside an off-peak window. A 7.4kW wall charger does it overnight, which is the difference between 2.3p and 8p a mile.