How to use this EV vs gas calculator
- Enter how many miles you drive a year.
- For the gas car, enter its fuel economy in mpg and your local gas price.
- For the EV, enter its efficiency in kWh per 100 miles, your home electricity price, a typical public charging price and how much of your charging happens at home.
- Enter how much less the EV costs to maintain each year and how much more it costs to buy.
- Compare the yearly costs, your annual savings and the payback period.
How it's calculated
Gas cost per year = annual miles ÷ mpg × gas price.
EV energy cost per year = annual miles × (kWh per 100 miles ÷ 100) × blended electricity price. The blended price weights your two charging sources: home share × home price + public share × public price. Energy lost while charging isn't added separately, so use an efficiency figure that already includes it.
Annual savings = gas cost − EV energy cost + the yearly maintenance difference. Payback years = EV price premium ÷ annual savings.
Example: you drive 12,000 miles a year. A 30 mpg gas car with gas at $3.50 costs $1,400 a year. An EV using 30 kWh per 100 miles, charged 80% at home for $0.16 per kWh and 20% in public for $0.45, has a blended price of $0.218. It uses 3,600 kWh a year, costing $784.80. That's $615.20 saved on energy, plus $400 less maintenance, for $1,015.20 a year. If the EV costs $6,000 more, it pays back in about 5.9 years.
Getting an accurate comparison
- Use the official efficiency rating from the window sticker. It's measured at the wall, so it already includes charging losses, while dashboard readings usually don't.
- Check your utility bill for the full price per kWh, including delivery charges, not just the energy charge.
- Be realistic about public charging. If you can't charge at home, set the home share low and expect smaller savings.
- Cold weather can raise energy use noticeably, so drivers in cold climates may want to enter a higher kWh per 100 miles figure.
- Compare insurance quotes too. EVs can cost more to insure, which the calculator doesn't include.
- Subtract any purchase incentive you're certain to receive from the price premium.
Good to know: A payback period only makes sense when annual savings are positive. Where public charging is expensive and home charging isn't possible, an EV may never earn back a higher price through running costs alone.
Frequently asked questions
Is charging an EV cheaper than buying gas?
For most drivers who charge mainly at home, yes, often by a wide margin. Relying heavily on public fast charging can shrink or erase the savings, because public prices per kWh are usually much higher than home electricity.
How much does it cost to charge an EV at home?
Multiply the energy used by your electricity rate. A car using 30 kWh per 100 miles at 16 cents per kWh costs about $4.80 per 100 miles. Time-of-use plans with cheaper overnight rates can lower that further.
Do electric cars really cost less to maintain?
Generally, yes. They need no oil changes, spark plugs or exhaust repairs, and regenerative braking reduces brake wear. Tires can wear faster because EVs are heavier, so the savings vary by vehicle.