Running cost comparison

EV vs Petrol Cost Calculator

Compare annual petrol or diesel fuel cost against EV electricity cost for the same UK mileage and see how tariffs change the saving.

EV cost = annual miles / miles per kWh x electricity price. Fuel cost = annual miles / MPG x 4.54609 x price per litre.

Choose the currency that matches the prices you enter. SaveWatt formats your result but does not convert exchange rates.

When EV savings look strongest

EVs often look strongest where most charging happens at home on a lower tariff and annual mileage is high enough to matter.

When savings shrink

If you rely heavily on public rapid charging or drive very few miles, fuel savings may be less important than purchase price and insurance.

Petrol, diesel and electricity inputs

Use your own fuel price per litre, real-world MPG and electricity price. Small differences in tariff or driving efficiency can change the yearly comparison.

EV vs petrol FAQ

Does this include insurance, tax and maintenance?

No. This page compares energy and fuel cost only. Ownership costs can change the full result.

Should I use real-world MPG?

Yes. Real-world MPG or consumption is better than brochure figures for a practical comparison.

Can I use this for diesel as well as petrol?

Yes. Enter your diesel price per litre and the car MPG to compare it with EV electricity cost.

Why does home charging change the result?

Cheap overnight charging can reduce EV running cost, while frequent rapid charging can reduce or remove the saving.