How much does it cost to charge an electric car?

The table shows a 20→80% charge — the everyday case, 60% of the pack — with 10% AC charging losses included. Multiply by 1.67 for a notional empty-to-full charge.

Charging at home is roughly 85–93% efficient. The onboard charger converts AC to DC and loses a little as heat, the pack’s internal resistance loses a little more, and thermal management runs while the car is plugged in. At 90% efficiency, a $0.18/kWh tariff delivers energy to the battery at an effective $0.200 per kWh stored.

Slow charging is proportionally worse, because the fixed overheads (electronics, pumps, cabin and battery conditioning) run for longer against a smaller energy flow. A 2.3 kW domestic socket can lose noticeably more than a well-matched wallbox delivering the same kWh in a third of the time.

Your tariff has structure too. Standing charges, network fees and taxes mean the effective per-kWh figure on your bill is usually above the headline unit rate, and a time-of-use plan can halve or double the cost of the same charge depending on when it happens.

Cost per distance is the number that compares with a petrol or diesel car, and it needs only two inputs: consumption and price. The chart uses $0.18/kWh with 10% charging losses; scale linearly for your own rate — double the price, double the bar.

Home charging cost is arithmetic. Public charging cost is a commercial tariff, and the structures differ enough that averaging them produces a meaningless number. What you can do is identify which structure you are paying under before you plug in.

Per-kWh tariffs

The cleanest case: the same formula as at home, with the operator’s price replacing yours. DC losses are lower than AC (the conversion happens in the charger, not the car), but you are billed at the charger’s meter, so a small delivery loss still sits between you and the pack.

Per-minute tariffs

Here your cost depends on how fast your car actually charges. A vehicle that peaks at 50 kW pays roughly three times as much per kWh as one peaking at 150 kW on the same post — and the taper above 80% makes the final percent extremely expensive. Where per-minute pricing applies, stopping earlier is a direct saving.

Session, connection and idle fees

Fixed fees dominate small top-ups: a $1 session fee on a 10 kWh charge adds $0.10/kWh. Idle fees charge for occupying the bay after charging completes.

Subscriptions

A monthly fee that lowers the per-kWh rate only pays back above a break-even volume. Divide the subscription cost by the per-kWh discount to get the kWh per month you must charge before it is worth having.

1. Charge on the cheapest tariff window. A time-of-use or dedicated EV rate is the single largest lever, and it costs nothing but a schedule in the car or the wallbox.

2. Charge at home where you can. Even an expensive residential tariff usually undercuts public rapid charging, which prices in hardware, grid connection and site costs.

3. Use a properly matched wallbox rather than a domestic socket. Higher power means fewer hours of fixed overhead per kWh delivered, so slightly less energy is wasted.

4. Precondition while plugged in. Heating the cabin and battery on grid power rather than pack energy moves that consumption to your cheapest rate and preserves range.