EV Charging Cost Per Charge Calculator
Charging an electric vehicle costs money for the energy you draw from the grid, and the real figure depends on your battery size, how much you top up, your electricity price and the efficiency of your charging equipment. This calculator takes those inputs and returns the energy added to the battery, the energy actually drawn from the wall (after charging losses), the cost of the charge in US dollars and the cost per mile. Your electricity rate and charging efficiency are inputs because they vary by utility, plan and hardware.
EV charging cost formula
Energy to battery (kWh) = capacity * charge percent / 100
Energy from wall (kWh) = energy to battery / charging efficiency
Cost (US$) = energy from wall * price per kWh
Cost per mile = cost / (energy to battery * miles per kWh)
Energy added to the battery is the usable charge; the grid must supply more than that because of charging losses, captured by the efficiency divisor. Cost is the wall energy times your rate. Cost per mile divides the charge cost by the driving range that charge provides.
EV charging context
- The U.S. Energy Information Administration publishes average residential electricity rates by state.
- Home AC charging efficiency is commonly 85 to 95 percent; DC fast charging losses differ.
- Time-of-use plans can sharply lower overnight charging cost; enter your applicable rate.
- Vehicle efficiency in miles per kWh varies with speed, terrain, climate and load.
- Public networks may add session or idle fees not included in a pure per-kWh price.
EV charging cost: frequently asked questions
How do you calculate the cost of charging an EV?
Energy added to the battery equals the battery capacity times the percent charged. Because charging is not perfectly efficient, the energy drawn from the wall is that figure divided by the charging efficiency. Multiplying the energy from the wall by your electricity price gives the cost.
Why is electricity price a user input?
Electricity rates vary by utility, plan, time of day and location, so there is no single correct figure. You enter your own rate in dollars per kilowatt-hour, which you can read from your utility bill. The U.S. Energy Information Administration publishes average residential rates for reference.
What is charging efficiency?
Charging efficiency is the fraction of energy drawn from the outlet that actually reaches the battery, after losses in the charger and battery. It is commonly around 0.85 to 0.95 for home AC charging. Enter the efficiency for your equipment; this calculator never assumes it.
How do I find cost per mile?
Enter your efficiency in miles per kilowatt-hour. The tool divides the cost of the charge by the miles that charge provides (energy to battery times miles per kWh) to give cost per mile, a useful figure for comparing with gasoline.
Does this include public fast-charging fees?
It computes cost purely from your entered price per kWh, so if you enter a DC fast-charging price it gives that cost. Some networks add session or idle fees not captured here. For home charging, the per-kWh rate is usually all that applies.
Official sources
- U.S. Energy Information Administration: Average Price of Electricity to Ultimate Customers.
- U.S. Department of Energy, fueleconomy.gov: Electric Vehicles: Charging and Efficiency.
Reviewed by the CalculatorHub team, edited by James Graham, 16 June 2026. See our methodology.