Data sources and calculations
Data last updated: 2026-01-01.
This site placeholder-fills state electricity and gasoline prices until the operator replaces them with sourced figures. The structure below is what production data will follow.
Electricity prices
Electricity figures are meant to track the U.S. Energy Information Administration's state-level average residential electricity price, published monthly in EIA's Electric Power Monthly. The value stored per state is cents per kilowatt-hour, residential rate class, most recent available month.
Gasoline prices
Gasoline figures are meant to track AAA's state average regular gasoline price, which AAA updates daily from its Daily Fuel Gauge Report. The value stored per state is dollars per gallon, regular grade, unweighted for city or region within the state.
How the main calculator works
Annual gasoline cost equals annual miles divided by MPG, multiplied by the state's gasoline price. Annual electricity cost equals annual miles divided by the EV's efficiency in miles per kWh, multiplied by the state's electricity rate. DC fast charging applies a 2.2× multiplier to the state's residential rate, approximating typical public fast-charging network pricing rather than home rates.
If you enter an EV price premium, break-even is the number of years until cumulative fuel savings offset that extra upfront cost: premium divided by (annual gas cost minus annual electricity cost). Leave the premium at zero to compare running costs only, with no purchase price assumption.
What isn't included
Maintenance, insurance, registration fees, depreciation, and incentives are not part of these calculations. Electricity and gasoline prices are state averages, not local or utility-specific rates — your actual bill may differ, sometimes by a wide margin depending on your utility and time-of-use plan.
Update schedule
The operator intends to refresh this data monthly. Each state page and the state data table display a "Data last updated" date so you can judge how current the figures are before relying on them.