EV vs Gas Savings Calculator
Compare energy cost only: wall electricity for an EV versus gasoline or petrol for a combustion car. Enter matching real-world efficiency and local prices; purchase, installation, maintenance, insurance and depreciation are excluded.
Quick answerAt 12,000 miles/year, 3.5 mi/kWh from the wall and $0.17/kWh, EV electricity costs about $582.86/year. A 30 mpg (US) car at $3.50/US gal costs $1,400/year, a difference of $817.14/year or $4,085.71 over five unchanged years.
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A negative number means petrol is cheaper at these prices.
At this electricity price, the modeled EV and gasoline/petrol energy cost per mile are equal.
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How it works
EV cost per mile = electricity rate ÷ wall mi/kWh. Gasoline/petrol cost per mile = price per U.S. gallon ÷ mpg (US). Annual costs multiply each result by annual miles. Savings = gasoline/petrol cost − EV cost. Break-even electricity rate = gasoline/petrol cost per mile × EV wall efficiency.
EV versus gasoline energy-cost examples
These scenarios use wall-to-road EV efficiency and U.S. gallons. They compare energy only and hold every input constant for the year.
| Scenario | EV annual cost | Gas annual cost | EV annual difference |
|---|---|---|---|
| 12k mi; 3.5 mi/kWh at $0.17; 30 mpg at $3.50 | $582.86 | $1,400.00 | $817.14 saved |
| 10k mi; 3.5 mi/kWh at $0.17; 30 mpg at $3.50 | $485.71 | $1,166.67 | $680.95 saved |
| 15k mi; 3.0 mi/kWh at $0.25; 30 mpg at $3.50 | $1,250.00 | $1,750.00 | $500.00 saved |
| 12k mi; 3.5 mi/kWh at $0.30; 40 mpg at $3.00 | $1,028.57 | $900.00 | $128.57 more |
| 12k mi; 4.0 mi/kWh at $0.10; 25 mpg at $4.00 | $300.00 | $1,920.00 | $1,620.00 saved |
Results exclude charging equipment, installation, public-charging session/idle fees, purchase price, tax, incentives, financing, maintenance, insurance and depreciation.
Worked example: 12,000 miles per year
The EV uses 12,000 ÷ 3.5 = 3,428.57 wall kWh/year. At $0.17/kWh, electricity costs $582.86. The 30 mpg car uses 12,000 ÷ 30 = 400 U.S. gallons; at $3.50/gallon, fuel costs $1,400. The energy-cost difference is $817.14/year.
Multiplying by five gives $4,085.71 only if mileage, efficiency and prices stay unchanged. It is not a forecast of total ownership savings.
Use wall-to-road EV efficiency
EPA says its EV MPGe values assume Level 2 AC charging and include losses from the charging cable/EVSE and onboard charger. Convert an EPA label by dividing 100 by its kWh/100-mile value. For example, 28 kWh/100 mi equals about 3.57 mi/kWh from the wall.
A dashboard may report battery-to-road efficiency instead. For a fair bill comparison, use wall kWh divided by miles or first add charging losses with the EV charging-cost calculator.
Keep gallons and mpg on the same basis
This page uses miles per U.S. gallon and price per U.S. gallon. UK imperial gallons are larger, so entering UK mpg with a U.S.-gallon price would mix unit systems. Convert both values to a common basis before comparing.
If fuel is sold by the litre, multiply price per litre by 3.785411784 to get price per U.S. gallon. If distance is tracked in kilometres, convert the complete scenario consistently rather than changing only one field.
What the comparison deliberately excludes
Energy cost is only one part of ownership. The calculator excludes vehicle purchase price, trade-in value, tax, incentives, financing, home-charging equipment and installation, maintenance, insurance, registration, parking and depreciation. Public charging may also add session, time or idle fees not represented by a home per-kWh rate.
Use the result as one transparent line item. DOE’s Vehicle Cost Calculator can support a broader model-by-model comparison where U.S. vehicle data is appropriate.
Sources used for assumptions: U.S. EPA — EV fuel-economy testing and charging-loss treatment; U.S. EPA — electric-vehicle label and kWh per 100 miles; U.S. Department of Energy AFDC — home-charging cost per mile; U.S. Department of Energy AFDC — Vehicle Cost Calculator.
Frequently asked questions
How do I compare EV and gas cost per mile?
Divide electricity price by wall mi/kWh for the EV. Divide price per U.S. gallon by mpg (US) for gasoline or petrol. The calculator performs both.
Does EPA EV efficiency include charging losses?
Yes. EPA says MPGe assumes Level 2 AC charging and includes EVSE/cable and onboard-charger losses, so its kWh/100 mi value is suitable for a wall-energy comparison.
How do I convert kWh/100 miles to mi/kWh?
Divide 100 by kWh/100 mi. For example, 28 kWh/100 mi equals about 3.57 mi/kWh.
Does this include public charging?
Only if you enter a representative all-in per-kWh equivalent. Session, minute, idle, parking or subscription fees must be added separately.
Does this include purchase price or maintenance?
No. It compares energy only. Purchase, financing, incentives, charging installation, maintenance, insurance and depreciation require a broader ownership model.
Can I enter UK imperial mpg?
Not directly. This calculator uses miles per U.S. gallon and price per U.S. gallon. Convert imperial mpg and fuel price to a consistent U.S.-gallon basis first.
What is the break-even electricity rate?
It is the electricity price at which the modeled EV and gasoline/petrol energy cost per mile are equal, holding both efficiencies and the fuel price constant.
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