Two formulas, one comparison
An electric car's energy cost depends on how many kilowatt-hours it uses per mile and what a kWh costs you. A gas car's depends on its miles per gallon and the price of a gallon.
The kWh per 100 miles figure is on the EPA label of every electric car. fueleconomy.gov describes it as how many kilowatt-hours the vehicle would use to travel 100 miles, an estimated rate of consumption. Use it rather than MPGe when you work with money: MPGe compares energy content, while kWh per 100 miles multiplies straight into your electricity price.
The official numbers used here
To keep the comparison fair, all five cars are the same size. fueleconomy.gov lists them as small sport utility vehicles, model year 2026, with these combined ratings:
| Vehicle (2026) | Type | EPA combined rating |
|---|---|---|
| Chevrolet Equinox EV FWD | Electric | 31 kWh/100 mi |
| Hyundai Ioniq 5 RWD | Electric | 30 kWh/100 mi |
| Chevrolet Equinox FWD | Gasoline | 27 mpg |
| Hyundai Tucson FWD | Gasoline | 28 mpg |
| Hyundai Tucson Hybrid | Hybrid | 36 mpg |
The Equinox comes as a gas and an electric model, which makes it the cleanest pair. The Tucson Hybrid in that listing has all-wheel drive, the others drive two wheels.
For prices, this guide uses the US Energy Information Administration (EIA) for both fuels. Its Electric Power Monthly put the average residential electricity price at 18.19 cents per kWh for January to July 2026, from 12.36 cents in North Dakota to 46.28 cents in Hawaii. Its weekly survey put regular gasoline at $4.331 a gallon as the US average for the week of October 12, 2026, with $3.779 in Texas and $6.104 in California.
Worked example at US average prices
The electric Equinox: 31 kWh per 100 miles is 0.31 kWh per mile. At $0.1819 per kWh: 0.31 × 0.1819 = $0.06, about 5.6¢ a mile.
The gas Equinox: $4.331 ÷ 27 mpg = $0.16, about 16.0¢ a mile.
Over 15,000 miles that is $846 of electricity against $2,406 of gasoline, a difference of $1,560. fueleconomy.gov makes a similar estimate on its own listing, $700 a year for the electric and $2,400 for the gas model, based on 15,000 miles a year, 55% city and 45% highway driving and the fuel prices the site uses. The gas figures nearly match. The site's electricity figure is lower, which means it works with a lower electricity price than the EIA average used here.
Against the Tucson Hybrid at 36 mpg the gap narrows: $4.331 ÷ 36 = about 12.0¢ a mile, or $1,805 over 15,000 miles. The electric car still costs less per mile at average prices, by about $959 a year.
Cost per mile at different prices
Prices vary much more between states than efficiency varies between these cars. Here are the electric cars at four real electricity prices and the gas cars at three real gasoline prices, all from the EIA figures above. The last column is the energy cost for 15,000 miles.
Electric cars
| Electricity price | Chevrolet Equinox EV | Hyundai Ioniq 5 | 15,000 mi, Equinox EV |
|---|---|---|---|
| North Dakota, 12.36¢/kWh | 3.8¢/mi | 3.7¢/mi | $575 |
| US average, 18.19¢/kWh | 5.6¢/mi | 5.5¢/mi | $846 |
| California, 33.25¢/kWh | 10.3¢/mi | 10.0¢/mi | $1,546 |
| Hawaii, 46.28¢/kWh | 14.3¢/mi | 13.9¢/mi | $2,152 |
Gas cars
| Gasoline price | Chevrolet Equinox | Hyundai Tucson | Hyundai Tucson Hybrid | 15,000 mi, Equinox |
|---|---|---|---|---|
| Texas, $3.779/gal | 14.0¢/mi | 13.5¢/mi | 10.5¢/mi | $2,099 |
| US average, $4.331/gal | 16.0¢/mi | 15.5¢/mi | 12.0¢/mi | $2,406 |
| California, $6.104/gal | 22.6¢/mi | 21.8¢/mi | 17.0¢/mi | $3,391 |
Read the two tables together, and match states where you can. In California, charging at the state's average residential price costs 10.3¢ a mile in the electric Equinox, against 22.6¢ for the gas Equinox and 17.0¢ for the hybrid at California gas prices. The gap shrinks where electricity is expensive and gas is cheap. At Hawaii's average of 46.28 cents per kWh the electric Equinox costs 14.3¢ a mile, a little more than the gas Equinox at Texas gas prices, 14.0¢, and clearly more than the hybrid at Texas prices, 10.5¢. Hawaii is not in the EIA's weekly gasoline table, so that pairing mixes two states to show the extreme case.
Where the answer flips
Turn the formulas around and you get the electricity price at which the EV costs exactly as much per mile as the gas car. Above it, gas is cheaper per mile; below it, electricity is.
| Compared with | Gas at $3.78 | Gas at $4.33 | Gas at $6.10 |
|---|---|---|---|
| Chevrolet Equinox FWD (27 mpg) | 45¢/kWh | 52¢/kWh | 73¢/kWh |
| Hyundai Tucson FWD (28 mpg) | 44¢/kWh | 50¢/kWh | 70¢/kWh |
| Hyundai Tucson Hybrid (36 mpg) | 34¢/kWh | 39¢/kWh | 55¢/kWh |
These are the break-even prices for the electric Equinox at 31 kWh per 100 miles. At US average gas, it stays cheaper per mile than its gas twin up to about 52 cents per kWh, and cheaper than the hybrid up to about 39 cents.
The same question from the other side: at the US average electricity price, gasoline would have to fall to about $1.52 a gallon for the 27 mpg Equinox to match its electric version, and to about $2.03 for the 36 mpg hybrid.
Home charging is billed at your residential rate. Public chargers set their own prices, so check the price at the charger and compare it with the break-even line for your car. The EV charging cost calculator lets you enter a home and a public price and a charging loss, and compares the result with a gas car.
Run it with your own numbers
- Your electricity price. Divide the usage charges on your bill by the kWh used. If you charge on a time-of-use plan, use the rate for the hours you charge.
- Your real efficiency. The trip computer shows it as miles per kWh or kWh per 100 miles. A long-term average beats a single trip. The fuel economy converter turns mpg into L/100 km and back if your figures come in different units.
- Your real mpg. Fill the tank, drive, fill it again and divide miles by gallons. The MPG calculator does it and explains why your figure can differ from the sticker.
- A specific trip. The trip fuel cost calculator gives the gas cost for one route, and the EV charging cost calculator does the same per mile for electricity.
- The whole car. Energy is only part of the cost. The cost per mile calculator adds depreciation, insurance, maintenance and the rest you enter.
For the units behind all of this, the kW vs kWh guide explains why a charger is rated in kW but your bill counts kWh.
What this comparison leaves out
This page compares energy cost per mile only. Purchase price, financing, insurance, depreciation, taxes, registration fees and incentives all differ between cars and states and are not included. On maintenance, the Department of Energy's Alternative Fuels Data Center says all-electric vehicles typically require less maintenance than conventional vehicles: fewer fluids such as engine oil, less brake wear thanks to regenerative braking, and far fewer moving parts. It also notes that a battery replacement outside the warranty is expected to be a significant expense, and that many manufacturers offer 8-year or 100,000-mile battery warranties. It gives no dollar figure for routine maintenance, so this guide does not put one on it.
The EPA ratings are estimates from standard tests. Your own driving, weather, speed and tires move both the kWh per mile and the mpg, so the two tables are a starting point and your own numbers in the calculators are the final word.
Frequently asked questions
How do I work out the cost per mile of an EV?
Multiply the kWh per mile by your price per kWh. The EPA label gives kWh per 100 miles, so divide by 100 first. At 31 kWh per 100 miles and 18.19 cents per kWh: 0.31 × $0.1819 = about 5.6 cents a mile.
How do I work out the cost per mile of a gas car?
Divide the price per gallon by the miles per gallon. At $4.331 a gallon and 27 mpg: 4.331 ÷ 27 = about 16 cents a mile. The trip fuel cost calculator does this for any trip.
At what electricity price does an EV stop being cheaper?
Divide the gas price by the gas car's mpg times the EV's kWh per mile. For the 27 mpg gas Equinox at the US average of $4.331 a gallon, against its electric version at 0.31 kWh per mile, the line sits at about 52 cents per kWh. Against a 36 mpg hybrid it drops to about 39 cents.
Does this include maintenance, insurance and depreciation?
No. This guide compares the energy cost only. The Department of Energy says all-electric vehicles typically need less maintenance than conventional ones, but it gives no dollar figure, so none is used here. For the full running cost of a car, including depreciation, insurance and repairs, use the cost per mile calculator.
What is MPGe?
Miles per gallon equivalent. fueleconomy.gov defines it as the miles a vehicle can go on electricity with the same energy content as a gallon of gasoline, counted as 33.7 kWh. It compares energy use, not cost. For money, use kWh per 100 miles and your electricity price.
Sources
- fueleconomy.gov (US EPA and DOE), 2026 Chevrolet Equinox FWD, Equinox EV FWD, Hyundai Tucson FWD and Ioniq 5 RWD side by side
- fueleconomy.gov (US EPA and DOE), 2026 Hyundai Tucson Hybrid
- fueleconomy.gov, Learn more about the fuel economy label for electric vehicles
- US Energy Information Administration, Electric Power Monthly, table 5.6.B: average price of electricity by state, year to date through July 2026
- US Energy Information Administration, Gasoline and Diesel Fuel Update, retail prices for the week of October 12, 2026
- US Department of Energy, Alternative Fuels Data Center, Maintenance and safety of electric vehicles