EV vs petrol cost comparison calculator UK
Find out exactly how much you could save by switching from a petrol car to an electric vehicle — based on your actual mileage, your current fuel costs, and your home electricity rate.
How much cheaper is an electric car than petrol in the UK?
For most UK drivers, switching from a petrol car to an EV saves between £1,000 and £2,000 per year on fuel costs alone. At the current UK average petrol price of around 148p/litre, a typical petrol car doing 10,000 miles per year at 35 mpg costs approximately £1,870 in fuel. The same mileage in an EV at home charging rates costs around £645 — a saving of over £1,200.
EV vs petrol running costs — UK comparison table
| Scenario | Cost per mile | Annual cost (10k miles) | vs petrol saving |
|---|---|---|---|
| Petrol car (35 mpg, 148p/litre) | ~18.7p | ~£1,870 | — |
| EV — standard rate (24.5p/kWh) | ~6.4p | ~£645 | ~£1,225/yr |
| EV — Octopus Go (7.5p/kWh) | ~2.0p | ~£197 | ~£1,673/yr ⚡ |
| EV — Octopus Intelligent (~7p/kWh) | ~1.8p | ~£184 | ~£1,686/yr ⚡ |
| Diesel car (45 mpg, 155p/litre) | ~15.9p | ~£1,590 | — |
| Petrol hybrid (50 mpg, 148p/litre) | ~13.1p | ~£1,307 | — |
What about insurance, servicing, and depreciation?
This calculator covers fuel costs only. The full picture is more complex — EVs typically cost more to insure (though this gap is closing), but cost significantly less to service with no oil changes, fewer brake replacements (regenerative braking), and fewer moving parts overall. Most EV owners report total running cost savings of £1,500–£2,500 per year when all factors are included.
Does it make financial sense to switch to an EV?
For most drivers who cover 8,000 miles or more per year and can charge at home, the answer is yes — particularly on a smart EV tariff. The main consideration is the higher purchase price of EVs vs equivalent petrol cars, which typically takes 3–5 years of fuel savings to offset depending on the models compared. However, with the 2035 petrol ban approaching, the used EV market is maturing rapidly and the price gap is narrowing.
How accurate is this calculator?
The calculator uses real-world efficiency figures for each EV model and current UK fuel and electricity prices. Actual savings will vary based on driving style, weather conditions (EVs are less efficient in cold weather), and whether you charge primarily at home or use public chargers. Public rapid charging at 60–85p/kWh significantly reduces the cost advantage of EVs vs petrol.
Frequently asked questions
How much does it cost to run an electric car per mile in the UK?
At the standard UK electricity rate of 24.5p/kWh, most EVs cost between 5p and 7p per mile to run at home. On a smart EV tariff like Octopus Intelligent at 7p/kWh, this drops to 1.5–2p per mile — compared to 15–20p per mile for a typical petrol car at current fuel prices.
How much does an electric car save per year vs petrol?
For an average UK driver doing 10,000 miles per year, switching from a 35 mpg petrol car to an EV charged at home on a standard tariff saves around £1,200 per year. On an Octopus Intelligent smart tariff at 7p/kWh, the saving increases to over £1,600 per year. Higher mileage drivers save proportionally more.
Is it cheaper to drive an EV or a petrol car in 2026?
For fuel costs alone, EVs charged at home are significantly cheaper — typically 3–4 times cheaper per mile than petrol. However, EVs generally have higher purchase prices and insurance costs. For drivers who cover more than 8,000 miles per year and can charge at home, the total cost of ownership typically favours EVs within 3–5 years.
What is the real-world efficiency of popular UK EVs?
Real-world efficiency varies by model and conditions. In moderate UK weather, typical figures are: Tesla Model 3 SR (~3.8 mi/kWh), VW ID.4 (~3.4 mi/kWh), Nissan Leaf (~3.5 mi/kWh), Hyundai Ioniq 5 (~3.7 mi/kWh), and MG4 (~3.6 mi/kWh). In winter these figures typically drop by 15–25%.
Does this calculator include public charging costs?
No — this calculator assumes all EV charging is done at home. Public rapid charging typically costs 60–85p/kWh, which significantly reduces the cost advantage over petrol. For drivers without home charging, the economics of EV ownership are less favourable. Use our home charging cost calculator to model your exact situation.
How does petrol price affect the comparison?
Every 10p/litre increase in petrol price adds approximately £130 per year to the cost of a 35 mpg car doing 10,000 miles. The calculator uses the current UK average but you can enter your local price for a more accurate result. The EV cost advantage grows as petrol prices rise.