Estimate only. Time-of-use rates, public fast charging and cold weather change the real cost.
How the cost is calculated
- Electricity: miles per month × your EV's energy use (kWh per 100 miles) ÷ 100.
- Charging cost: that electricity × your state's average residential price (EIA, Table 5.6.B).
- Gasoline cost: miles per month ÷ the gas car's mpg × the price per gallon.
Which energy use to enter
Use the kWh/100 mi from your EV's EPA label or fueleconomy.gov. If you use the number on your car's screen instead, it may count only the energy in the battery: add charging losses, since charging efficiency is often 84% to 93% (fueleconomy.gov).
Default values
- Gasoline: $3.10 per gallon, the 2025 U.S. average for regular gasoline (EIA). Prices vary by state and week.
- Gas car: 27.2 mpg, the average real-world fuel economy of new model year 2024 vehicles (EPA Automotive Trends).
If your utility has a cheaper overnight rate for EV charging, your savings will be higher than shown.