EV Charging Cost Calculator
Enter your car, your mileage and where you charge. We count charging losses, which most calculators quietly skip — they add about 10% to your real bill.
How this is calculated
Three steps, all shown so you can check them:
- Energy at the battery. Miles divided by your efficiency in miles per kWh. Drive 13,500 miles at 3.5 mi/kWh and the battery delivers 3,857 kWh.
- Energy at the meter. Divide that by charging efficiency. At 90%, 3,857 kWh at the battery means 4,286 kWh billed. That extra 429 kWh is real and it is on your bill.
- Cost. Multiply by your rate, splitting home and fast charging because they are priced very differently.
The mistake most calculators make
They stop after step one. Skipping charging losses understates your annual cost by around 10% — roughly $75 a year for a typical driver. Small, but it is exactly the kind of quiet omission that makes an EV look better on paper than it is in your bank account.
What actually changes the answer
Where you charge — by far the biggest factor
Home electricity averages about 17.5¢/kWh. DC fast charging commonly runs 40–60¢. Shifting from 10% fast charging to 100% can more than double your annual cost without changing a single mile driven. If you cannot charge at home, run that number before buying an EV — it is the single most important input on this page.
Winter
Cold weather is brutal for EV efficiency. Heating the cabin draws from the same battery that moves the car, and a cold battery is less efficient before you even move. Expect 20–30% worse consumption in a genuine winter, sometimes 40% on short trips where the car never warms through. To model this, lower your efficiency figure rather than raising your mileage.
Speed
Aerodynamic drag rises with the square of speed. Sustained 75 mph motorway driving can consume 30% more per mile than mixed suburban driving — the reverse of a petrol car, which is usually most efficient on the motorway.
A worked example
| Scenario | Rate | Annual cost | Per mile |
|---|---|---|---|
| All home, off-peak tariff | $0.09 | $386 | 2.9¢ |
| All home, standard rate | $0.1745 | $748 | 5.5¢ |
| 90% home / 10% fast | mixed | $797 | 5.9¢ |
| All DC fast charging | $0.48 | $1,969 | 14.6¢ |
13,500 miles at 3.5 mi/kWh. Home charging at 90% efficiency, fast charging at 94%.
Worth sitting with: the gap between the best and worst row is $1,583 a year — larger than the difference between most EVs and most petrol cars. Where you charge matters more than what you drive.
Comparing against petrol
Charging cost alone does not tell you whether an EV saves money. Use the EV vs gas comparison, which puts both fuels on the same footing.
Assumptions
- US average residential electricity: $0.1745/kWh (EIA)
- Average annual mileage: 13,500 (FHWA)
- Level 2 home charging efficiency: 90%; 120V outlet: 80%; DC fast: 94%
All are editable above, and all are sourced on our methodology page.
Common questions
Why is my cost higher than the manufacturer's figure?
Manufacturers quote efficiency at the battery under ideal test conditions. Your electricity meter measures what comes out of the wall, which is 6–15% higher because of charging losses. Cold weather, short trips and motorway speeds all push real consumption further above the official rating — 20–30% worse in winter is normal.
What are charging losses exactly?
Converting AC from your wall into DC in the battery wastes energy as heat, and the car also runs cooling pumps and electronics while charging. A home Level 2 charger is typically 85–90% efficient. A slow 120V outlet can drop to 80% because the car's overheads run for far longer. DC fast charging is the most efficient at roughly 92–95%.
Is charging at home always cheaper?
Almost always, and usually by a lot. Home electricity averages about 17 cents per kWh in the US, while DC fast charging commonly runs 40–60 cents. That is a 3x difference. If you rely mainly on fast charging, an EV's running-cost advantage over petrol can shrink to almost nothing — try setting the fast-charging share to 100% above and compare.
Should I get a time-of-use tariff?
If you can charge overnight, usually yes. Many utilities offer EV or off-peak rates around 8–12 cents per kWh versus 17+ cents standard, which can roughly halve your charging bill. The catch is that off-peak plans often raise your daytime rate, so it only pays if the bulk of your household usage — not just the car — can shift to off-peak hours.