EV vs Gas: The Real Cost per Mile

Published 2026-03-10 · By the CalculatorHive editorial team

The "EVs are cheaper to run" claim is usually true and occasionally false, and which one applies to you comes down to two numbers: what you pay for energy, and how efficiently your car converts it into miles. This guide gives you the formulas, a comparison table across the price ranges people actually face, and the adjustments — charging losses, cold weather, fees, depreciation — that separate a marketing figure from a real one. It does not tell you which to buy. That depends on facts about your life that no calculator has.

What are the two cost-per-mile formulas?

For a gasoline or diesel car:

Cost per mile = fuel price per gallon ÷ MPG

At $3.50 a gallon and 30 MPG, that is $3.50 ÷ 30 = $0.1167, or 11.7 cents per mile. If you only know your fuel-ups rather than a window-sticker figure, the MPG calculator derives real-world MPG from miles driven and gallons purchased, which is usually 5–15% worse than the EPA combined rating.

For an electric car:

Cost per mile = electricity price per kWh ÷ miles per kWh

At $0.16/kWh and 3.5 mi/kWh, that is $0.16 ÷ 3.5 = $0.0457, or 4.6 cents per mile.

Efficiency is quoted three ways and they are all the same fact. The EPA prints kWh per 100 miles on the window sticker; 3.5 mi/kWh is 28.6 kWh/100mi. MPGe converts using the EPA's constant of 33.7 kWh per gallon of gasoline equivalent, so 3.5 mi/kWh is about 118 MPGe. MPGe is useful for comparing two EVs and useless for comparing an EV to a gas car, because a kWh and a gallon cost nothing like the same.

How do the numbers compare across real prices?

Electricity varies far more by region and time of day than gasoline does, so a single answer is meaningless. Here is the grid. Electric figures assume the plug-to-wheels efficiency shown, before charging losses.

The pattern is clear. An EV charged at home beats almost any gasoline car by a wide margin; an EV charged exclusively on DC fast networks lands in the same band as an efficient hybrid, and can lose to one. The EV vs gas calculator runs both formulas side by side with your own rate and MPG.

Worked example: 12,000 miles a year

Take a 3.5 mi/kWh EV and a 30 MPG gasoline car, both driven 12,000 miles a year, with electricity at $0.16/kWh at home, $0.48/kWh on the fast-charge network, and gasoline at $3.50.

The arithmetic: 12,000 ÷ 3.5 = 3,429 kWh delivered to the wheels. At home, divide by 0.88 to account for a 12% charging loss, giving 3,896 kWh on the meter, times $0.16 = $623. The gas car burns 12,000 ÷ 30 = 400 gallons at $3.50 = $1,400. The home-charging EV saves about $777 a year; the fast-charge-only EV saves nothing.

Note that the DC fast row skips the loss adjustment. Fast chargers bill for energy measured at the dispenser, after the AC-to-DC conversion has already happened in the charger rather than in the car, so the loss is mostly not on your bill. Home AC charging is the opposite: the meter counts everything, including what the onboard charger and battery thermal management waste.

Why is public charging so much more expensive than home?

Public DC fast charging commonly runs two to three times a residential rate, sometimes more. Three things drive it: the hardware costs six figures per site and has to amortise; commercial electricity tariffs include demand charges billed on the highest kilowatt draw in the month, which a 350 kW charger triggers instantly; and the network wants a margin. Some operators also bill by the minute rather than the kWh, which penalises cars that charge slowly or arrive with a warm battery, and some add idle fees after your session ends.

Subscription plans typically cut the per-kWh rate by 10–25% for a monthly fee, which pays off only above a threshold you can work out from the two rates. The EV charging cost calculator handles per-session costs including battery size, starting and target state of charge, and charger rate.

The practical consequence: if you cannot charge where you park overnight, model your costs on the public rate, not the residential average. That flips the answer for a lot of apartment dwellers.

What about charging losses and cold weather?

Charging losses are the gap between the kWh your utility meters and the kWh that end up in the battery. Level 1 (120 V) charging is the worst, because the car's overhead runs for many more hours per kWh delivered. Level 2 (240 V) is better. A reasonable planning figure is 10–15%, so multiply your calculated energy cost by about 1.10–1.15 if your efficiency figure is measured at the wheels. Most trip computers report miles per kWh consumed by the car, not miles per kWh bought, which is why owners who compare the dashboard to the electric bill find a discrepancy.

Cold weather hits efficiency hard, and the mechanism is worth understanding. A gasoline engine is about 25–30% efficient, so it throws off enough waste heat to warm the cabin for free. An EV has almost no waste heat, so cabin heating comes out of the traction battery — a resistive heater can draw 3–6 kW, which at 30 mph is the same energy as moving the car. Add cold-stiffened lubricants, battery preconditioning, denser air, and winter tires, and freezing-weather efficiency commonly falls 20–40% below the mild-weather figure. Heat-pump-equipped cars fare better, and gasoline cars also lose efficiency in winter, but by a much smaller margin.

If you are budgeting a journey rather than a year, the trip fuel cost calculator and the fuel cost calculator let you enter a seasonal efficiency figure instead of the sticker number.

What the per-mile figure leaves out

Fuel is one line in a total cost of ownership, and it is not usually the biggest one. The honest comparison includes:

• Purchase price and depreciation. Comparable EVs still often cost more up front, and depreciation is typically the largest single ownership cost for any new car. A per-mile fuel saving of 6¢ is $720 a year — real money, but small next to a few thousand dollars of price difference.
• Incentives. Federal, state, and utility incentives for vehicles and home chargers change frequently and carry income, price, and sourcing conditions. Check the current rules for your situation rather than a figure you read last year.
• Maintenance. EVs have no oil changes, spark plugs, timing belts, exhaust systems, or transmission fluid, and regenerative braking makes brake pads last far longer. Against that, EVs are heavier and torquier and go through tires faster.
• Road-use fees. Fuel taxes fund roads — the federal gasoline excise tax alone is 18.4 cents a gallon — and EVs pay none of it, so many states levy an annual EV registration surcharge instead, commonly in the $50–$250 range. Add $150 to the home-charging example above and the per-mile cost goes from 5.2¢ to 6.4¢.
• Insurance. Often higher for EVs, largely because battery-pack damage can total a car that would otherwise have been repairable.
• Battery warranty. In the United States, EV traction batteries carry a federally mandated minimum warranty of 8 years or 100,000 miles, and some states require longer. Read what it actually promises: most guarantee against capacity falling below a stated percentage (commonly 70%), not against gradual degradation above it.

Common questions

How do I find my car's actual miles per kWh?

Reset a trip computer and drive normally for a few hundred mixed miles; most EVs report mi/kWh or kWh/100mi directly. For the number that matches your electric bill, take a full month of charging-session kWh from the charger app or a submeter and divide the month's odometer miles by it. That figure already includes charging losses, so do not apply the 10–15% adjustment on top.

Does charging at work or on a free charger make an EV free to run?

For the energy, effectively yes, which is why workplace charging is one of the strongest arguments for an EV. It does not change depreciation, insurance, tires, or the state registration surcharge, and free chargers have a habit of becoming paid ones. Model the decision on what you would pay if the free access disappeared.

Is a hybrid a better answer than either?

Sometimes. A 50 MPG hybrid at $3.50/gal costs 7.0¢ a mile, which beats an EV charged entirely at public DC rates and loses to one charged at home. The comparison turns on whether you can charge overnight where you park — if you can, the EV usually wins on fuel; if you cannot, the efficient hybrid is frequently cheaper.

How many miles does it take to make up a higher purchase price?

Divide the price difference by the per-mile fuel saving. A $6,000 premium against a 6.5¢ per mile saving is 6,000 ÷ 0.065 = about 92,000 miles — roughly eight years at 12,000 miles a year. Adjust that for incentives you actually qualify for, for lower maintenance, and for any registration surcharge, and treat it as an estimate rather than a forecast, since both electricity and gasoline prices will move over that horizon.