EV Charging Cost Calculator

Enter your battery size, the state of charge you start and finish at, and the price you pay for electricity, and this calculator shows what one charging session costs, including the energy lost while charging. Add your car's efficiency from its EPA label and your monthly mileage to get the cost per mile and per month, the MPGe rating, and a comparison with a gasoline car, including the electricity price at which the two cost the same to fuel.

energy into battery = battery kWh × (end % − start %)

energy from outlet = energy into battery ÷ charging efficiency

session cost = energy from outlet × price per kWh + any fees

cost per mile = kWh per 100 miles ÷ 100 × price per kWh; MPGe = 33.7 ÷ kWh per mile

The EPA counts one gallon of gasoline as 33.7 kWh for MPGe. EPA efficiency figures are measured from the wall, so they already include charging losses; the per-mile cost uses them directly, while the session estimate applies your charging efficiency to the energy added to the battery.

Home charging. Adding 20% to 80% to a 75 kWh battery puts 45 kWh in the battery and draws 50.0 kWh at 90% efficiency. At $0.17 per kWh that costs $8.50.

DC fast charging. From 10% to 80% at $0.48 per kWh costs about $27.39, nearly three times the home rate for a similar amount of energy.

Monthly driving. At 30 kWh per 100 miles and $0.17, 1,000 miles cost $51.00, against $116.67 for a 30 mpg car with gasoline at $3.50. The EV costs more to fuel only above about $0.39 per kWh.

Some energy is lost as heat in the charger, the cable and the battery. Level 2 home charging typically delivers around 85 to 95% of the energy drawn, while a standard 120-volt outlet tends to be less efficient because the car's systems run for many more hours during a slow charge. Cold weather adds battery heating. If you can read the kWh used from your charger or utility app, divide the energy added to the battery by it to find your own efficiency.

Use the usable battery capacity, which is a little smaller than the gross figure some brochures quote. Many owners charge to 80% for daily driving to reduce battery wear and save 100% for long trips, as their manufacturer recommends; the cost per mile does not change with these habits, only the size of each session. Charging speed also slows above about 80% on fast chargers, so stopping there often saves time on road trips.

Many utilities offer time-of-use or EV plans with much cheaper electricity overnight. Scheduling charging for off-peak hours can cut the cost per mile substantially. Public charging is priced by kWh in most states, but some networks charge by the minute or add idle fees; enter any fixed fee in the session fee field. Solar panels can lower the effective rate further, which the solar panel calculator can estimate.