eGallon Calculator: Gas Price Equivalent of Electricity
The U.S. Department of Energy's eGallon is the cost to drive an EV as far as a comparable gas car goes on one gallon. Enter your own numbers.
How it works
DOE's formula: eGallon ($/gal) = FE × EC × EP, where FE is the comparable gasoline car's fuel economy (miles per gallon), EC is the EV's consumption (kWh per mile) and EP is the electricity price ($/kWh). Break-even electricity price = gasoline price ÷ (FE × EC).
Worked example: DOE's example: 27.9 mpg × 0.326 kWh/mi × $0.1269/kWh = $1.15 per eGallon. With 30 mpg, 30 kWh/100 mi and $3.60 gas, break-even electricity is $3.60 ÷ 9 kWh = $0.40 per kWh.
Assumptions
- DOE's published eGallon uses national or state averages for FE, EC and EP; this calculator lets you use your own vehicles and prices.
- Energy cost only; vehicle purchase, maintenance and fees are excluded.
- Constant efficiency for both vehicles.
- All prices are editable estimates. The defaults are placeholders, not current market prices; use your own bill or charger's posted price.
Frequently asked questions
What is an eGallon?
The U.S. Department of Energy defines the eGallon as the cost of driving an electric vehicle the same distance a gasoline-powered vehicle could travel on one gallon of gasoline.
How does DOE calculate it?
eGallon = average comparable car fuel economy (mi/gal) × average EV electricity consumption (kWh/mi) × average electricity price ($/kWh). DOE's 2016 example: 27.9 × 0.326 × $0.1269 = $1.15 per gallon.
Related calculators
- Gas vs electric cost per mile
- EV charging cost calculator
- MPGe, kWh/100 mi and miles/kWh converter
- EV home charging cost per month
- kWh to BTU, joules and therms converter
Sources
Formulas and reference values are from these sources. Page last reviewed 2026-10-19.