EV Charging Cost Calculator

How to use the EV charging cost calculator

Enter the battery size, the state-of-charge window you are charging across, your electricity rate, and under Advanced the charging efficiency, and the tool returns the cost of that charge plus the cost of an equivalent full 0 to 100 percent charge. Use the usable capacity your manufacturer quotes rather than the gross pack size, since the buffer between them can be several kilowatt-hours. The rate is the input worth checking most carefully: the Energy Information Administration put the US residential average at 18.44 cents per kilowatt-hour in May 2026, with state averages that month spanning 12.35 cents in Idaho to 52.00 cents in Hawaii, so an average is a placeholder. If your utility offers an overnight EV tariff, that is the number to enter.

Home versus public is the whole cost story of owning an electric car. Charging at home on a residential rate is the cheap case this tool models by default. Public Level 2 costs more, and DC fast charging costs considerably more per kilowatt-hour, because you are paying for hardware, grid capacity, and convenience rather than just energy. Networks price it differently and often dynamically: Electrify America, for instance, states that its pricing is determined by charger location, your plan, and the amount of energy delivered, and shows the price at the charger before a session begins. The arithmetic does not change at all, so to price a public session simply enter that station rate in place of your home rate.

The 20 to 80 percent default reflects how electric cars are actually used. Most charging happens in the middle of the pack rather than end to end, because charging the last stretch to 100 percent slows down markedly and regularly sitting at full or running near empty is harder on lithium cells. Widen the window when you genuinely need the range for a long trip and leave it alone for daily driving. Charging speed depends on where you plug in: the Department of Energy Alternative Fuels Data Center describes AC Level 1 at 120 V and about 1.9 kW adding roughly 5 miles of range per hour, AC Level 2 at 240 V and 2.9 to 19.2 kW with most residential units at 7.2 kW adding about 25 miles per hour, and DC fast charging adding roughly 100 to 200 or more miles in 30 minutes.

Charging losses are real and this tool charges you for them. Energy is lost to heat, to the AC-to-DC conversion in the onboard charger, and to battery thermal management before it reaches the cells, which is why the Advanced efficiency setting defaults to 90 percent and the grid energy comes out higher than the energy landing in the pack. Worth knowing: the EPA already accounts for this in its window-sticker figures. Its own description states that MPGe values assume Level 2 AC charging and account for losses from the charging cable and the onboard charger, moving the measurement to the wall outlet. So if you work from an EPA kilowatt-hours per 100 miles rating, multiply by your rate directly rather than applying an efficiency factor a second time.

The formula

Energy into the battery is the usable capacity multiplied by the size of the charge window. Energy drawn from the grid is higher than that, because some of what you pull from the wall never reaches the cells, and the cost is the grid figure multiplied by your rate. That ordering matters: you are billed at the meter, not at the battery terminals.

The equivalent full-charge figure at the bottom of the results answers a different question. It prices a notional 0 to 100 percent charge at the same rate and efficiency, which is a useful yardstick for comparing cars of different battery sizes even though few drivers ever charge that way in practice.

energy to battery = battery kWh x (to percent - from percent) / 100
grid energy = energy to battery / efficiency
cost = grid energy x rate
cost of a full charge = (battery kWh / efficiency) x rate

Worked example with the tool defaults, which are a 75 kWh battery taken from 20 to 80 percent at $0.175 per kWh with 90 percent charging efficiency. The window is 60 percent, so energy to the battery is 75 times 0.60, which is 45 kWh. Grid energy is 45 divided by 0.90, which is 50 kWh. Cost is 50 times $0.175, which is $8.75. The equivalent full charge is 75 divided by 0.90, which is 83.33 kWh, times $0.175, giving $14.58.

Turn that into miles and the comparison gets concrete. Those 50 kWh from the wall would take a 2026 Tesla Model Y Long Range RWD, rated by the EPA at 25 kWh per 100 miles, about 200 miles, so the $8.75 charge works out at roughly 4.4 cents a mile. Cover the same 200 miles in a 30 mpg gasoline car and you burn 6.67 gallons, which at the US average regular price of $4.001 per gallon for the week ending 20 July 2026 reported by the EIA comes to $26.67, or 13.3 cents a mile. Home charging is roughly a third of the fuel cost in that comparison.

Two caveats. First, do not double-count losses: the EPA figures used above are measured at the wall and already include Level 2 charging losses, so an efficiency divisor belongs in the battery-capacity calculation on this page and not in a per-mile calculation built from a window sticker. Second, this is an energy-cost estimate rather than a total cost of ownership figure and it is not financial advice; it excludes the installation cost of home charging equipment, network subscription fees, idle fees, and any taxes a jurisdiction applies to public charging.

Frequently asked questions