EV vs Gas Cost Calculator

What the calculator compares

An EV and a gas car both cost money to move, just in different ways. A gas car burns gallons; an EV pulls kilowatt-hours from the grid. This calculator puts both on the same footing so you can compare dollars per year instead of miles per gallon against miles per kilowatt-hour.

The math is short:

• Gas cost per year = (miles per year ÷ mpg) × price per gallon
• EV cost per year = (miles per year ÷ miles per kWh) × price per kWh

Feed in your own numbers above. A typical US driver covers about 12,000 to 13,000 miles a year, pays around $3.10 a gallon for regular gas, and pays roughly 16 to 17 cents per kilowatt-hour at home. Change any of those and the answer moves, which is exactly why a national average is a poor guide for your own decision.

The calculator also shows cost per mile, gallons and kilowatt-hours used, and how long it takes for the fuel savings to pay back a higher purchase price. Everything runs in your browser, nothing you type is uploaded or stored.

Worked example: 12,000 miles a year

Take a gas car that does 30 mpg and an EV that does 3.5 miles per kWh. Gas is $3.20 a gallon and home electricity is 17 cents per kWh. You drive 12,000 miles.

• Gas car: 12,000 ÷ 30 = 400 gallons × $3.20 = $1,280 a year
• EV: 12,000 ÷ 3.5 = 3,429 kWh × $0.17 = $583 a year
• Saving: $1,280 − $583 = $697 a year

Per mile that is 10.7 cents for the gas car and 4.9 cents for the EV, the electric car costs less than half as much to fuel. Over ten years the saving is about $6,970, and that is before you count the lower maintenance an EV needs.

The catch is the sticker price. If the EV costs $8,000 more than the gas car you would otherwise buy, the fuel saving of $697 a year takes $8,000 ÷ $697 = 11.5 years to break even. A federal tax credit of $7,500 shrinks that gap to $500 and payback to under a year.

Home charging vs public fast charging

The single biggest number in this whole comparison is what you pay per kilowatt-hour, and that depends on where you charge. Home electricity is cheap; public DC fast charging is not.

Run the same EV at a public fast charger priced at 45 cents per kWh: 3,429 kWh × $0.45 = $1,543 a year. That is $263 more than the gas car. A driver with no home charging who relies on fast chargers can end up spending more on energy than they would have on gasoline.

The sweet spot is charging at home overnight, ideally on a time-of-use plan where off-peak power can drop below 10 cents per kWh. At 10 cents, the yearly EV cost falls to about $343, a saving of more than $900 over the gas car. If you have rooftop solar, the effective cost can fall to 5 cents or less. This is why 'can I charge at home?' matters more than almost any spec on the car.

Annual energy cost at a glance

The table below compares yearly energy cost across common gas efficiencies and EV efficiencies, at 12,000 miles with gas at $3.20 a gallon and home electricity at 17 cents per kWh.

Two things stand out. First, the EV wins at every row on home charging, and it wins by the most when the gas car is thirsty. Second, a 45 mpg hybrid is close to a mid-range EV on energy cost, so if you drive a lot of highway miles a hybrid can be the cheaper choice overall. The US Department of Energy's fueleconomy.gov lets you look up the exact figures for any model you are considering.

Fuel is only part of the story

Energy cost is the easiest part of the comparison to measure, but it is not the whole bill. Over the life of a car, maintenance and repairs can swing the numbers as much as fuel does.

• Oil and filters. A gas car needs oil changes every 5,000 to 10,000 miles. An EV has none, saving $60 to $100 a service.
• Brakes. EVs use regenerative braking, so pads and rotors often last 100,000 miles or more instead of 40,000.
• Engine and transmission. An EV has far fewer moving parts, so fewer things break.
• Tires. Here the EV can cost more, the extra weight and instant torque wear tires faster.
• Battery. Modern packs are usually warranted for 8 years or 100,000 miles, so this is rarely an out-of-pocket cost for the first owner.

Add it up and studies typically put EV maintenance near 6 cents a mile against about 10 cents for a gas car. On 12,000 miles a year that is another $480 a year in the EV's favour, which can cut the payback period roughly in half.

How long until the EV pays for itself?

The payback question is simple arithmetic: divide the extra you pay for the EV by the money it saves you each year. The calculator does this for you, but the answer depends heavily on three things.

Your electricity price. Cheap off-peak power can double the yearly saving; expensive fast charging can erase it. Your gas price. The higher gas goes, the faster an EV pays off. The price gap. Tax credits and cheaper entry-level EVs shrink it fast. A $7,500 credit against an $8,000 gap leaves $500 to earn back, which the fuel saving covers in under a year.

For the wider picture on how energy prices move and how they feed into everything else you buy, see the US Energy Information Administration, which publishes monthly gasoline and electricity price data. The Alternative Fuels Data Center has state-by-state charging costs and a savings calculator of its own. One honest caveat: this tool compares energy cost, not total cost of ownership. Insurance, registration fees (some states charge EVs extra) and depreciation all matter, and only you can weigh those.