EV Charging vs Gas: What You Actually Save

The short version: if you charge at home, an EV is meaningfully cheaper to run per mile than a comparable gas car in most of the United States. The longer version is that the size of that gap varies enormously — by state, by utility tariff, by the car you are comparing against, and by whether you actually charge at home or end up relying on public fast charging.

Rather than quote you a national average that may be wrong for your situation by a factor of two, here is the calculator. Put in your own electricity rate, your own mileage and the gas car you are comparing against.

How the comparison actually works

Both sides reduce to cents per mile, and once you see it that way the whole thing becomes simple arithmetic.

The electric side. Your car has an efficiency in miles per kWh — a typical figure is somewhere around 3 to 4, with efficient small EVs higher and large trucks and SUVs lower. Divide your electricity rate in cents per kWh by that efficiency and you have cents per mile. At 18.3¢/kWh and 3.5 mi/kWh, that is about 5.2¢ per mile.

The gas side. Divide the gas price per gallon by the car’s MPG. At $4.09 a gallon and 28 MPG, that is about 14.6¢ per mile.

The gap between those two numbers, multiplied by your annual mileage, is your saving. The DOE and EPA use this same structure in their own cost-to-charge modeling on fueleconomy.gov, which is the authoritative source for the method rather than for your particular numbers.

The one adjustment worth making

Charging is not perfectly efficient. Some energy is lost as heat in the charger, the cable and the car’s onboard conversion, so the kWh your meter records is somewhat more than the kWh that reaches the battery. The practical way to handle this is to add roughly 10% to your calculated electricity cost. It narrows the gap slightly; it very rarely changes the conclusion. Our cost-to-charge guide goes into this in more detail.

Where the savings come from

Almost entirely from the price difference between residential electricity and retail gasoline per unit of useful energy, amplified by the fact that an electric drivetrain converts far more of its input into motion than an internal combustion engine does. That second factor is structural and does not change with market conditions; the first varies constantly.

Which means the honest answer to “how much will I save?” is: it depends on where you live. US residential electricity prices vary by more than a factor of three between the cheapest and most expensive states, and gas prices swing regionally too. Someone with cheap hydro power and expensive gasoline sees a dramatic difference. Someone in a high-electricity-cost state comparing against an efficient hybrid may see very little.

The two things that erase the savings

1. Charging mostly in public

This is the big one. DC fast charging is priced well above residential electricity — it has to be, because the equipment is expensive and the utility demand charges are substantial. At the higher end of public pricing, on an inefficient vehicle, the cost per mile can approach or exceed that of a fuel-efficient gas car.

So the savings case for an EV is really a home charging case. If you have no reliable way to charge where you park overnight, run the numbers on public rates before assuming the economics work. Our AC vs DC charging guide explains why fast charging costs what it does.

2. Ignoring the up-front cost

A Level 2 charger and its installation are real money that a gas car does not require, and the install is frequently the larger half. To be honest with yourself, divide that total across the years you expect to own the car and add it to your per-mile figure.

This rarely reverses the comparison, but it does push the break-even out. It is also the reason the budget charger questionmatters more than the specification arguments — and why sizing to a circuit your panel already supports, rather than buying amperage that forces a panel upgrade, is the single biggest lever on your total cost. Our amps and circuits guide covers that sizing decision.

Things that quietly improve the number

Time-of-use rates.If your utility charges different prices by hour, charging overnight can cut your electricity cost substantially — sometimes by half. This is the single largest lever available to most home charger owners, it requires no hardware change, and either your car or your charger can automate it. If your utility offers an EV tariff, look at it before anything else.

Efficiency in your control. Miles per kWh responds to driving style, speed, tire pressure and climate control in the same way MPG does. A difference between 3 and 4 mi/kWh is a 25% difference in your running cost.

Maintenance, which is outside this calculation.No oil changes, no exhaust system, no spark plugs, and far less brake wear because of regenerative braking. We have deliberately not modeled it here because it varies too much by vehicle to estimate honestly — but it sits on the electric side of the ledger, and it is not nothing.

Cold weather, honestly

Winter costs more per mile. Efficiency drops because energy goes into heating the battery and the cabin, and charging losses rise in the cold. A calculation done in July flatters the EV; an annual average is the honest figure. Cabin preheating while still plugged in helps, because that energy comes from the wall rather than the battery.

Working out your own number

Three figures, all of which you can find in a few minutes:

Your real electricity rate.From your bill, not a national average. Take the total dollar amount and divide by the kWh used — that captures delivery charges and fixed fees rather than just the generation rate. If you would charge on an off-peak tariff, use that rate.

Your car’s real efficiency. The dashboard readout over a few months is more accurate than the EPA figure, and it already includes your driving and your climate.

The gas car you are actually comparing to. Be fair here. Comparing an EV against a large truck produces a flattering number that tells you nothing useful if the alternative you would really have bought is an efficient hybrid.

Put those into the calculator above and you have a number that applies to you rather than to a national average. If you want the absolute monthly cost instead of the comparison, our cost-to-charge-at-home guide works that side of it.