Electric vs Gas Car Cost Calculator
This compares running costs only — the fuel or electricity to move the car. Purchase price, insurance and depreciation are handled separately by the ownership calculator, and they usually matter more than the numbers here.
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Where the saving comes from
An electric motor converts far more of its stored energy into motion than a combustion engine does, and electricity is generally cheaper per unit of energy than refined fuel. Those two effects compound, which is why the cost per mile usually lands somewhere between a third and a half of the petrol equivalent.
But the size of the gap depends almost entirely on two numbers you should check rather than assume: the price you pay for electricity, and the price of fuel where you live. In places with cheap electricity and expensive petrol the gap is dramatic. Where electricity is expensive and fuel is cheap it can nearly vanish.
Charging at home versus charging in public
Home charging on a standard domestic tariff is where the savings live, and it gets better still on an overnight or time-of-use tariff, which can be a fraction of the daytime rate. Public rapid charging is a different product at a different price — often three or four times the home rate, sometimes approaching the per-mile cost of petrol.
If you cannot charge at home, model your real mix rather than the home rate. Enter a blended price that reflects how much of your charging is realistically going to happen on public networks.
What this calculator deliberately leaves out
Running cost is not the whole comparison. Electric cars typically cost more to buy and have historically depreciated differently from petrol equivalents, while needing less routine servicing — no oil changes, far less brake wear thanks to regenerative braking. Purchase incentives, where they exist, can swing the total either way. Run both cars through the ownership calculator to see the full picture.
Frequently asked questions
How many miles per kWh does an EV get?
Most current electric cars manage somewhere between 3 and 4 miles per kWh in mixed driving, which is roughly 5 to 6.5 kilometres per kWh. Small efficient models do better; large SUVs and pickups do considerably worse. Cold weather can cut it by a fifth or more.
Why do I need to account for charging losses?
Not all the electricity your meter records reaches the battery - some is lost as heat in the charger and the battery itself. You pay for what the meter records, so the calculator grosses the energy up accordingly. Around 10% is typical for home AC charging.
Does cold weather change the answer?
Yes, and more than for a petrol car. Cabin heating draws directly from the battery, and a cold battery is less efficient. Winter range losses of 20 to 30 percent are common. If you live somewhere cold, lower the efficiency figure to see the annual effect.
Do EVs really need less maintenance?
There is less to service: no oil, no spark plugs, no exhaust system, and regenerative braking means brake pads often last far longer. Tyres tend to wear faster because the cars are heavier. On balance, routine servicing costs are usually lower.