What an electric car costs to “fill up” depends far more on where you charge than on the car itself. Plugging in at home overnight can cost a third of what the same energy costs at a highway fast charger. This calculator blends the two at the ratio you choose, turns it into a cost per mile, month and year, and lines it up against a gasoline car.
How to use the EV charging cost calculator
- Enter your EV’s energy use. The EPA label figure in kWh per 100 miles is the best source; you can also enter mi/kWh, Wh/mi or kWh/100 km.
- Enter your miles per year.
- Enter your home electricity rate from your utility bill and a typical public fast-charging rate in your area.
- Set the share of charging done at home. Drivers with a home charger often do 80% or more at home; apartment dwellers may rely on public charging.
- Optionally enter the battery size, plus a gas car’s mpg and the gas price for a comparison.
How charging cost is calculated
For the gas comparison, the cost per mile is simply the gas price divided by mpg. The break-even electricity price — where the EV and the gas car cost the same per mile — is the gas cost per mile divided by the EV’s kWh per mile.
Worked example
An EV rated 30 kWh/100 mi is driven 12,000 miles a year. Home power costs $0.18/kWh and fast charging $0.45/kWh, with 80% of charging at home.
kWh per mile = 30 ÷ 100 = 0.30
Blended price = 0.8 × 0.18 + 0.2 × 0.45 = $0.234 per kWh
Cost per mile = 0.30 × 0.234 = 7.02¢ → $842.40 a year ($70.20 a month)
Gas car: 12,000 ÷ 30 mpg × $4.35 = $1,740 → EV saves $897.60 a year
Charging only at home would cut the bill to $648 a year; relying entirely on fast chargers would push it to $1,620 — barely below the gas car.
Where the numbers come from
The default electricity price is close to the US average residential rate of about 18.3 cents per kWh that the US Energy Information Administration (EIA) reported for July 2026, and the default gas price reflects the EIA’s national average for regular gasoline of about $4.35 a gallon in early October 2026. Both vary a lot by region and season, so replace them with your own figures. The MPGe conversion uses the EPA’s equivalence of 33.7 kWh per gallon of gasoline.
Ways to lower your charging cost
- Charge off-peak. Many utilities sell overnight electricity at a discount, sometimes through an EV rate plan.
- Use Level 2 at home. A 240-volt charger makes it practical to do nearly all charging at home rather than at fast chargers.
- Treat fast charging as a road-trip tool. Stopping at 80% is quicker and often cheaper per mile driven, because charging slows sharply near full.
- Watch the weather. Cabin and battery heating can raise winter energy use noticeably; enter a higher kWh/100 mi to model it.
Compare your current car’s fuel use with the gas mileage calculator, convert efficiency figures with the fuel economy converter, or price other household loads with the electricity cost calculator.
These results are estimates for budgeting, not financial advice. Real costs depend on your rate plan, charger fees, driving style, temperature and battery condition.
Frequently asked questions
How much does it cost to charge an electric car?
Multiply the car's energy use by your electricity price and miles driven. An EV using 30 kWh per 100 miles costs $5.40 per 100 miles at an 18-cent home rate, or about $648 a year for 12,000 miles. Public fast charging at 45 cents per kWh would cost $13.50 per 100 miles.
Do EPA kWh/100 mile ratings include charging losses?
Yes. The EPA measures the electricity drawn from the wall outlet, so the label figure already includes losses in the charging cable and on-board charger — roughly 10% according to fueleconomy.gov. Add extra losses only if you use the car's own dashboard efficiency, which measures energy leaving the battery.
What is the average US electricity price?
The US Energy Information Administration reported an average residential price of about 18.3 cents per kWh for July 2026, but rates vary widely by state and utility. Your bill shows your actual rate, and many utilities offer cheaper overnight or EV-specific time-of-use rates.
How is MPGe calculated?
MPGe divides 33.7 — the EPA's kWh-equivalent of one gallon of gasoline — by the kWh the car uses per mile. A car using 30 kWh per 100 miles (0.30 kWh per mile) is rated about 112 MPGe.
At what electricity price does an EV cost the same as gas?
Divide the gas car's cost per mile by the EV's kWh per mile. With $4.35 gas and a 30-mpg car (14.5 cents a mile) against an EV using 0.30 kWh per mile, the break-even is about 48 cents per kWh — above typical home rates but close to many fast-charging prices.