Electric Vehicle Fuel Savings Calculator

The two numbers that decide it: cost per mile

Comparing an electric car with a gas car comes down to one comparison: dollars per mile. Everything else, gallons, kilowatt hours, miles per gallon, is a step on the way there. Once both cars are expressed as a cost per mile, the annual savings is just miles driven times the difference.

For the gas car, divide the price of a gallon by the miles per gallon. At $4.35 a gallon and 28 mpg, that is 4.35 / 28 = $0.155 per mile. For the EV, divide the price of a kilowatt hour by the miles per kilowatt hour, then divide again by the charging efficiency, because some of the electricity you pay for never reaches the battery.

Those two divisions are where most comparisons go wrong. A common mistake is to compare the price of a gallon with the price of a kilowatt hour directly, which is meaningless because a gallon holds about 33.7 kWh of energy and an EV uses it three to four times as efficiently. The U.S. Department of Energy fuel economy site puts EV tank to wheel efficiency above 77%, against 12% to 30% for a gasoline engine.

Charging loss: why the wall costs more than the battery

When you pay for electricity, you pay at the meter, not at the battery. Energy is lost in the onboard charger, in the cable, in heat, and in the battery itself. The Department of Energy puts charging efficiency at 84% to 93%, which means 7% to 16% of the electricity you buy never turns into miles.

That loss is small per mile and noticeable per year. At 3.5 miles per kWh and 18.31 cents per kWh, the battery level cost is 0.1831 / 3.5 = $0.0523 per mile. Divide by 0.90 for a 10% loss and the wall level cost is $0.0581 per mile. On 12,000 miles that is $627.77 against $697.52, a difference of $69.75 a year.

DC fast charging loses more and costs more. A public fast charger can run 40 to 60 cents per kWh, which pushes the per mile cost above a gasoline car in some states. Home charging at off peak rates is where the savings live, and that is the number this calculator assumes.

Worked example: 12,000 miles in a 28 mpg car and a 3.5 mi/kWh EV

The defaults on this page use the 2026 U.S. averages from the Energy Information Administration: $4.354 a gallon for regular gasoline in the week of October 5, 2026, per the EIA gasoline and diesel update, and 18.31 cents per kWh for residential electricity in July 2026, from the Electric Power Monthly end use tables. The gas car gets 28 mpg, the EV gets 3.5 miles per kWh, charging loses 10%, and the EV costs $5,000 more to buy.

Twelve thousand miles is close to the U.S. average of about 13,500 miles a year per driver, so the default is a reasonable stand in. If you drive 15,000 miles, every line scales by 1.25: $2,330 for gas, $872 for electricity, and $1,458 saved.

The EV also draws about 3,810 kWh from the wall each year at these numbers, which is roughly a third of what a typical U.S. home uses. That matters if you are on a time of use plan, since moving those miles to overnight hours can cut the electricity price in half.

How much the gap in price costs you

The fuel savings only matter against what you paid to get them. A $5,000 price gap cleared at $1,167 a year takes 4.3 years. A $9,000 gap takes 7.7 years. If you keep the car less than that, the fuel savings never catch up, and the EV is a cost, not a saving.

The same $5,000 gap takes 6.4 years at 8,000 miles a year and 3.4 years at 15,000. Mileage is the lever, and it is the one number you can estimate with confidence from your own odometer. Look up last year's mileage rather than guessing, since the answer moves by years, not months.

Tax credits change the gap, and they change often. If a credit applies, subtract it from the price gap before you run the payback, because the credit is money you never spend. If the credit has expired, use the sticker difference and nothing else.

What electricity and gas prices do to the answer

Fuel prices are not national. The EIA reported residential electricity at 18.31 cents per kWh nationwide in July 2026, with California at 30.71 cents, Massachusetts at 26.56 and North Dakota at 9.09. Gasoline in the same period ran $4.354 a gallon nationally, with the West Coast near $5.73 and the Gulf Coast near $3.91.

Those spreads push the per mile comparison around a lot. Cheap electricity and expensive gas favor the EV by a wide margin. Expensive electricity and cheap gas narrow it to a few cents, and in the worst case the EV costs more per mile than a 40 mpg hybrid.

Read the table by finding your state's electricity price and your local gas price. In the cheapest corner, a California driver paying 30.71 cents and $5.00 gas still saves 8 cents a mile, which is $973 a year at 12,000 miles. In the other corner, a North Dakota driver at 9 cents and $3.50 gas saves 9.6 cents a mile, or $1,157 a year.

What the calculator leaves out

Fuel is not the whole cost of ownership, and the omissions cut both ways. Leaving them out keeps the comparison honest about what it measures: energy per mile, nothing else.

• Maintenance. An EV has no oil changes, no spark plugs and no exhaust, and regenerative braking stretches brake pads. A typical EV saves $300 to $500 a year here, which shortens the payback.
• Tires. EVs are heavier and wear tires faster, often 20% to 30% sooner. That costs $200 to $400 a year more and partly offsets the maintenance saving.
• Insurance and registration. EVs often cost more to insure because of repair costs, and many states now charge an annual EV fee of $100 to $250 to replace gas tax revenue.
• Home charging equipment. A Level 2 charger and installation runs $500 to $1,500, which is a real cost if you do not already have a 240 volt outlet.
• Resale value. Battery health and model turnover move resale more than fuel savings ever will.

For most drivers the maintenance saving roughly cancels the tire, insurance and registration costs, which is why this page sticks to fuel. If you want the full picture, add the items above to the annual savings before you divide the price gap.

Why the price gap matters more than the fuel math

Fuel savings are predictable and small. A price gap is large and fixed. That asymmetry means the purchase decision is mostly about the gap, and the fuel math only tells you how fast you earn it back.

A useful rule: divide the price gap by the annual fuel saving to get years, then compare that with how long you plan to keep the car. Most people keep a new car 6 to 8 years. A payback longer than that is a bet on gas prices rising, and a payback under 4 years is close to a sure thing at current prices.

The other number worth computing is break even mileage. Take the gap and divide by the saving per mile: $5,000 / $0.0972 = 51,424 miles. If you drive 12,000 miles a year, that is 4.3 years of driving, which is the same answer from the other direction. Both routes are useful, and they should always agree.

Getting a number that fits your own driving

Four inputs drive the result, and you can replace every default with something real. Use your own annual miles from the odometer, your local gas price from the station you use, your home electricity rate from a recent bill, and the efficiency of the specific EV you are considering from its window sticker.

Efficiency is the input people guess worst. A large electric pickup can run 2.0 to 2.3 miles per kWh, while a small sedan can reach 4.5. At 18.31 cents, that is $0.102 per mile against $0.045, a difference of more than a factor of two. Check the miles per kWh figure on the sticker rather than assuming a class average.

Finally, run the numbers twice, once with your current car and once with the car you are considering. The comparison that matters is between two specific vehicles, not between categories. A 45 mpg hybrid is a hard benchmark, and an EV that saves 3 cents a mile against it takes a long time to clear a $6,000 gap.