How Much Does It Cost to Charge an Electric Car?

Charging is priced per unit of energy — the kilowatt-hour (kWh). To estimate the cost of a full charge, multiply your battery size (in kWh) by the local price per kWh. A 50 kWh battery at a price of 0.30 per kWh costs about 50 × 0.30 = 15 for a full charge, in whatever your local currency is. That's the core of it.

The three places you'll pay different prices

• Home — usually the cheapest, especially on an off-peak overnight tariff. This is where most EV owners do most of their charging.
• Public AC — a little more than home, since you're paying an operator for the equipment and the parking spot.
• Public DC rapid — the most expensive per kWh, because rapid chargers are costly to install and draw a lot of power. You pay for the speed.

Watch for extra fees

Some operators add a session fee (a fixed charge per plug-in) or an idle fee (a per-minute penalty for leaving the car connected after it's finished, to keep bays free). These can make a small top-up disproportionately expensive, so for short charges it's worth checking them. ChargEV shows the per-kWh price, session fee and idle fee — in the operator's own currency — for any station whose owner has published them.

A worked example

Say you drive 1,200 km a month in a car that uses about 16 kWh per 100 km. That's roughly 192 kWh a month. Charged mostly at home at 0.20 per kWh, that's around 38 a month for all your driving. The same distance in a petrol car at 6 litres/100 km and a fuel price of 1.50 per litre would be about 108. The exact numbers depend on your prices, but the pattern — home charging costing a fraction of fuel — holds almost everywhere.

Public rapid charging narrows the gap: relying entirely on expensive DC chargers can cost as much as fuel. The big savings come from charging at home or work whenever you can, and using rapid charging for trips.