EV Charging Cost Calculator

This EV charging calculator answers three questions at once: what one charging session costs, what you pay per mile, and how a month of driving compares with a gasoline car. It works for any electric car. Enter your battery size, the charge window, your electricity rate and how efficient your car is. For Tesla presets, use the Tesla charging calculator. To see driving emissions next to your home energy use, try the carbon footprint calculator.

How to calculate EV charging cost

EV charging cost = kWh added to the battery ÷ charging efficiency × your price per kWh. Work out the kWh added from battery size and charge window, divide by about 0.9 for home charging losses, then multiply by the rate on your bill. Divide by miles added for cost per mile.

The calculator follows the energy from the wall to the wheels in four steps:

1. Energy added to the battery = battery size (kWh) × (charge to % − charge from %) ÷ 100
2. Energy from the wall = energy added ÷ charging efficiency
3. Cost of the charge = energy from the wall × price per kWh
4. Range added = energy added × car efficiency (mi/kWh), and cost per mile = cost ÷ range added

For the monthly comparison it divides your monthly miles by mi/kWh, adds charging losses and prices the result, then compares it with miles ÷ mpg × gas price.

Worked example with the default values

The defaults describe a mid-size EV charged at home at the US average price:

• Battery 75 kWh, charged from 20% to 80%: 75 × 60 ÷ 100 = 45 kWh added
• Charging efficiency 90%: 45 ÷ 0.90 = 50.0 kWh from the wall
• Price 18.2¢/kWh: 50 × $0.182 = $9.10 for the session
• Car efficiency 3.5 mi/kWh: 45 × 3.5 = 158 miles of range (157.5)
• Cost per mile: $9.10 ÷ 157.5 = 5.8¢

For 1,000 miles a month: 1,000 ÷ 3.5 ÷ 0.90 = 317.5 kWh from the wall, which costs $57.78. The same miles in a 28 mpg car at $4.28 a gallon (the EIA US regular average for the week of October 19, 2026) use 35.7 gallons and cost $152.86, so the EV saves about $95.08 a month on energy.

The 18.2¢ default is the US average residential price from the EIA Electric Power Monthly (18.16¢, August 2026). Your bill rate may be much higher or lower.

EV charging cost reference table

Cost of adding 45 kWh to the battery (90% efficiency, 50 kWh from the wall) at different electricity prices:

The fast-charging row assumes you pay for the kWh delivered by the charger, so the 90% home loss is not applied. Fast chargers still have losses, but they are on the station’s side of the meter.

What affects the result

• Your real electricity price. Use the all-in price from your bill, including delivery charges. The cost per kWh calculator works it out from your bill total. Time-of-use and EV-specific rates can cut the cost of overnight charging sharply.
• Charging efficiency. Level 2 (240 V) charging usually lands at roughly 85–95% efficiency (Recurrent). Level 1 (120 V) charging, the cordset supplied with most cars (DOE AFDC), takes longer, so fixed loads such as battery conditioning eat a larger share. Very cold weather can lower efficiency further.
• Car efficiency. EVs convert over 77% of grid energy to power at the wheels (fueleconomy.gov), but mi/kWh still varies with speed, temperature, tires and climate control. Highway driving in winter can cut it by a quarter or more. Use your car’s trip computer average for the best estimate.
• Usable vs total battery. Enter the usable capacity. Manufacturers often quote a larger gross figure.
• Charge window. Daily top-ups from 20% to 80% cost far less per session than a full 0–100% charge, but the cost per mile stays the same.
• Charger circuit. A faster Level 2 charger needs a bigger circuit. Use the kW to amps calculator to find the breaker size for a 7.2 kW or 11.5 kW charger.

Do incentives change the math?

The federal §30D clean vehicle credit ended for vehicles acquired after September 30, 2025 (IRS), so this calculator does not include any purchase credit. Running-cost savings are what’s left. Some utilities still offer EV charging rates or charger rebates, so check your provider.

References

• SAE International. J1772: SAE Electric Vehicle and Plug in Hybrid Electric Vehicle Conductive Charge Coupler (2024 revision). sae.org
• U.S. Department of Energy, Alternative Fuels Data Center. Charging Electric Vehicles at Home. afdc.energy.gov
• U.S. DOE / EPA. All-Electric Vehicles, fueleconomy.gov. fueleconomy.gov

For a full walk-through of home, public and workplace charging costs, read our guide on the cost to charge an electric car. If kWh, kW and mi/kWh are still fuzzy, start with what a kilowatt-hour is. To price any other appliance in the house, use the electricity cost calculator.