An electric car's running cost depends on its efficiency and what you pay for electricity, just as a gas car's depends on MPG and the pump price. This calculator puts both on the same footing: cost per mile, per year and over the years you'll keep the car.
How the comparison works
- EV cost per mile = (kWh per 100 miles ÷ 100) × your blended price per kWh.
- Blended price = your home rate and your public fast-charging rate, weighted by the share of miles you charge each way.
- Gas cost per mile = gas price ÷ MPG.
- Yearly cost = cost per mile × miles per year.
For example, an EV using 30 kWh/100 mi on $0.16/kWh home power costs 4.8 cents a mile. A 30-mpg car on $3.50 gas costs 11.7 cents a mile. Over 12,000 miles a year that's about $576 vs $1,400.
Why we use kWh per 100 miles
MPGe (miles per gallon equivalent) is printed on window stickers, but it's hard to turn into dollars. The EPA also publishes kWh/100 mi, and that's what you need: it multiplies straight into your electricity rate. The EPA measures it from the wall outlet, so normal charging losses are already included.
The inputs that matter most
- Your electricity rate. Look at your utility bill for the price per kWh, including delivery charges. Time-of-use plans can make overnight charging much cheaper.
- How much you fast-charge. Public DC fast charging usually costs several times the home rate. Drivers who can't charge at home should set this share high.
- Your gas price and MPG. Compare with the gas car you'd otherwise buy, not with your current car, if that's the real decision.
The break-even gas price shows the pump price at which both cars cost the same per mile with your inputs.
What this doesn't include
Energy is only part of the picture. Purchase price, tax credits and incentives, insurance, home charger installation, tires and maintenance all differ between EVs and gas cars. For the whole picture, run each car through the cost of ownership calculator, and read our EV vs gas cost guide.
Frequently asked questions
Is it cheaper to charge an EV than to buy gas?
For most drivers who charge mainly at home, yes, often by more than half per mile. Drivers who rely on public fast charging can see much smaller savings, and in some cases none.
How do I find my electricity price per kWh?
Divide your bill's total energy charges by the kWh used, or look for the rate on the bill. Include delivery charges, not just the supply rate.
What is a good kWh per 100 miles?
Lower is better. Many compact and midsize EVs are rated around 25–35 kWh/100 mi; large SUVs and trucks use more. Pick your EV above to use its EPA rating.
Does cold weather change the result?
Yes. EVs typically use more energy in cold weather for cabin and battery heating, and gas cars lose some efficiency too. Use a higher kWh/100 mi if you live somewhere cold.
Results are estimates from the numbers you enter and, where noted, EPA ratings. Not financial advice. Page updated .