EV vs. gas: what does 100 miles really cost?
Start with one fact: a gallon of gasoline contains 33.7 kilowatt-hours (kWh) of energy — about 34 kWh. That's the same unit on your electric bill. Once fuel and electricity are measured in the same unit, the comparison is simple math. Change any number below and watch it update.
⛽ Gasoline car
- 1Fuel needed
100 mi ÷ mpg = gal - 2Energy in that fuel
gal × 33.7 kWh/gal = kWh - 3Cost
gal × $ = - 4Per mile
÷ 100 = /mile
Fuel used for 100 miles
Can holds 5 gallons.
🔌 Electric car
- 1Energy needed
100 mi × kWh/100 mi = kWh - 2In gallons of gas energy
kWh ÷ 33.7 = gal-equivalent → MPGe - 3Cost
kWh × $ = - 4Per mile
÷ 100 = /mile
Electricity used for 100 miles
Shown against a 75 kWh battery pack.
Same trip, very different energy
Both cars need roughly the same energy at the wheels to move 100 miles. The difference is how much gets wasted on the way. A gasoline engine turns most of its fuel into heat: only about 16–25% reaches the wheels. An EV delivers about 87–91%, counting regenerative braking.
The gas car burns × more energy for the same 100 miles.
The bottom line
Over miles a year: gas vs. electric — a difference of .
Break-even: at these numbers, electricity would have to cost /kWh before the EV costs as much per mile as gas. Equivalently, the EV is like paying per gallon of gas.
☀️ Power it with sunshine instead. How many solar panels would it take to charge your EV? See the math →Fuel cost only. It doesn't include purchase price, insurance, maintenance (EVs have no oil changes), or tax credits.
Sources
- AAA Gas Prices — national average regular gasoline; public EV charging average.
- EIA Electric Power Monthly — average U.S. residential electricity price.
- EPA / fueleconomy.gov — 1 gallon of gasoline = 33.7 kWh (basis of MPGe).
- EPA Automotive Trends Report — average new gas vehicle real-world fuel economy.
- fueleconomy.gov: Where the Energy Goes (gas) and (electric) — energy to the wheels.