EV vs Gas Car Cost Calculator

Almost every electric-versus-petrol comparison starts and ends with energy cost, and on that measure the argument is not close. An efficient electric car uses about 30 kilowatt-hours per hundred miles; at a residential rate of 18.44 cents that is roughly five and a half cents a mile. A petrol car at 28 mpg with fuel at $4.10 costs about fourteen and a half cents a mile. The electric car is around a third of the cost per mile.

The reason that does not settle anything is that fuel is not where most of the money goes. Over eight years and 96,000 miles, the example above spends about $6,600 on electricity or $14,000 on petrol — while losing $25,200 or $22,100 respectively in depreciation. The single largest cost of owning any car is the difference between what you paid and what you sell it for, and it is roughly double the fuel bill in both columns.

This is why the comparison so often comes out closer than either camp expects, and why it hinges on inputs that have nothing to do with energy: what the two cars cost, what they are worth in eight years, and how much your insurer charges.

Beyond energy, two real structural advantages show up in the maintenance line, and one disadvantage.

This single input moves the answer more than anything else on the page, and it is the one most comparisons treat as an afterthought.

Charging at home overnight costs the residential electricity rate — nationally around 18.44 cents a kilowatt-hour in mid-2026, and considerably less on an overnight time-of-use tariff, where 10 to 13 cents is common. Charging at a DC fast charger typically costs 40 to 60 cents a kilowatt-hour, sometimes with an idle fee on top. That is a factor of three, and at the top of that range an electric car costs about the same per mile as a reasonably efficient petrol one.

The practical consequence is that "should I buy an EV" is really two different questions depending on where you park. With a driveway and a charger, 85 to 90% of charging happens at the cheap rate and the running-cost advantage is large and reliable. Without off-street parking, the same car might charge 40% in public, the blended rate roughly doubles, and much of the case evaporates — which is a real and underdiscussed equity problem in EV adoption rather than a quirk of the arithmetic.

The federal incentive landscape for electric vehicles was dismantled over nine months, and any comparison built before mid-2025 is now wrong in the same direction.

The One Big Beautiful Bill Act, enacted 4 July 2025, terminated the Section 30D credit for new clean vehicles — worth up to $7,500 — and the Section 25E credit for used ones, worth up to $4,000, for vehicles acquired after 30 September 2025. The IRS interpreted "acquired" as paid for, so a binding contract and payment before 1 October preserved eligibility even where delivery came later, but nothing bought since qualifies.

Section 30C, the credit for home charging equipment worth 30% up to $1,000, ran a little longer and ended for property placed in service after 30 June 2026. As of the second half of 2026 there is no federal purchase or charging incentive for an ordinary household buying an electric car.

State and utility programmes are a separate matter and several remain substantial — California, Colorado, New York and others run their own rebates, and many utilities subsidise home charger installation or offer a dedicated EV tariff. Those belong in the price and charger fields above, which is why this calculator asks for a net figure rather than applying an incentive of its own.

Every figure in this calculation is knowable except one. Purchase prices are on a window sticker, energy costs are on a bill, insurance is a quote, and maintenance follows a schedule. Resale value in eight years is a forecast, and it is simultaneously the largest number in the comparison and the least reliable.

Electric vehicle depreciation has been steeper and considerably more volatile than petrol depreciation, for reasons that are specific to a technology still moving quickly: buyers discount older battery chemistry and slower charging, new model prices have been cut abruptly, and a used EV market that is still forming prices uncertainty into every transaction. The end of the federal used-EV credit removed a floor under used prices as well.

The honest way to handle this is not to pick a number and trust it, but to run the calculation twice — once with an optimistic resale assumption and once with a pessimistic one — and see whether the conclusion survives both. If the electric car wins at 30% residual and at 50% residual, the decision is robust. If it flips somewhere in between, then you are not really making a cost decision, you are making a bet on the used market, and it is better to know that.