Fuel is the most visible saving from driving electric — you stop buying gasoline and start paying for electricity at a lower price per mile. How big the saving is, though, depends on four things you can look up or measure: the gas price, the car you are replacing, the electricity price and how much of your charging happens at home rather than at a pricey public fast charger. This calculator puts those together and projects the saving over several years, with optional fuel-price growth.
How to use the EV fuel savings calculator
- Enter your driving (miles per year) and the gas car you would replace: its mpg and the gas price.
- Enter the EV's consumption in kWh per 100 miles (the EPA label shows it).
- Enter electricity prices for home and public charging and the share of charging you do in public.
- Choose the number of years and, if you like, yearly price growth for gas and electricity.
- Read the yearly saving, the total over the period and the saving per mile.
For a one-line comparison with a break-even on the car's price premium, see the EV vs gas calculator; for one charging session, the EV charging cost calculator.
EV fuel savings formula
Gas cost = miles ÷ mpg × gas price
EV cost = miles × kWh per 100 miles ÷ 100 × blended price
Saving = gas cost − EV cost
With yearly growth r: total = cost × ((1 + r)^years − 1) ÷ r
- Public share is the fraction of your kWh bought away from home
- Growth rates apply to each fuel separately; leave them at 0 for constant prices
Worked example: 12,000 miles a year
- Gas car: 12,000 ÷ 30 × $3.50 = $1,400.
- Blended electricity: 0.17 × 0.8 + 0.40 × 0.2 = $0.216 per kWh.
- EV: 12,000 × 0.30 × 0.216 = $777.60.
- Saving: 1,400 − 777.60 = $622.40 a year, or $3,112 over 5 years.
How the gas price changes the saving
This table keeps the EV and driving the same and changes the gas price. Values are computed with the formula above.
| Gas price per gallon | Gas car per year | EV per year | Saving per year | Saving over 5 years |
|---|---|---|---|---|
| $3.00 | $1,200 | $778 | $422 | $2,112 |
| $3.50 | $1,400 | $778 | $622 | $3,112 |
| $4.00 | $1,600 | $778 | $822 | $4,112 |
| $4.50 | $1,800 | $778 | $1,022 | $5,112 |
| $5.00 | $2,000 | $778 | $1,222 | $6,112 |
What drives the saving
Three inputs matter most. The first is the car you are replacing: a 20-mpg SUV costs twice as much to fuel as a 40-mpg car, so the saving from going electric is far bigger. The second is where you charge. Public fast charging often costs two to three times what you pay at home, so a driver without home charging will save much less than one who plugs in overnight. The third is the electricity rate itself, which varies widely by region and time of day; a time-of-use plan for EVs can lower it further.
Prices change, and that is what the growth rates are for. If you think gasoline prices will rise faster than electricity, enter a higher growth for gas; the cumulative saving rises accordingly. Keeping both at zero gives the conservative, flat-price answer.
The calculator covers fuel only. EVs also tend to need less routine maintenance, but may cost more to buy and, in some places, to insure, and a home charger has an installation cost. To put the price premium on the same page use the EV vs gas calculator, and for the range side the EV range calculator. A hybrid is a middle path: see the hybrid vs gas calculator.
Sources
Per-model electricity consumption (kWh per 100 miles) and the way fuel economy is compared are published on the EPA/DOE fuel economy site (fueleconomy.gov). Local gas and electricity prices should come from your own bills and stations; national averages are published by the US Energy Information Administration. The calculation is arithmetic on the inputs; the table values were computed from the formulas shown.
Frequently asked questions
How much can I save by driving an EV?
It depends on your gas price, the car you are replacing, your electricity price and how much you drive. With the example inputs (12,000 miles, 30 mpg, $3.50 gas, 80% home charging) the saving is about $622 a year.
Why include public charging?
Public fast charging costs much more per kWh than home electricity. Mixing the two gives a more honest cost than assuming everything is charged at home.
Why the price-change inputs?
Fuel prices change over the years, so you can see the effect of gasoline getting more expensive or electricity prices rising. Leave them at zero for a flat-price comparison.
Does it include the car’s purchase price?
No. It covers only fuel and electricity. Use the EV vs gas calculator to find a break-even against a price premium, and consider insurance, maintenance and incentives separately.
What if the result is negative?
Then the EV costs more to fuel — possible when you compare to a very efficient hybrid, pay high electricity rates or charge mostly in public.