Quick answer
Compare both fuels in dollars per mile. Gas: price ÷ MPG. EV: kWh price ÷ miles per kWh. At $3.50/gal and 30 MPG, gas costs about $0.117/mi. At $0.16/kWh and 3.5 mi/kWh, an EV costs about $0.046/mi — roughly 60% less. Lean heavily on public DC fast charging at $0.40–$0.55/kWh and the EV number can climb past $0.13/mi.
The math
gas_cost_per_mile = price_per_gallon / mpg
ev_cost_per_mile = blended_kwh_price / miles_per_kwh
blended_kwh_price = home_share * home_price + (1 - home_share) * public_price
Worked example
| Input | Gas | EV |
|---|---|---|
| Efficiency | 30 MPG | 3.5 mi/kWh |
| Price | $3.50/gal | $0.16/kWh home, $0.45/kWh public |
| Charging mix | — | 80% home / 20% public |
| Blended energy price | — | $0.218/kWh |
| Cost per mile | ~$0.117 | ~$0.062 |
| Annual at 12,000 mi | ~$1,400 | ~$748 |
Why public charging matters so much
DC fast charging is commonly priced 2–4x residential electricity. A 20–30% public-charging share can add 1–3 cents per mile, which over 12,000 miles a year is $120–$360. If you can't charge at home reliably, run the numbers with a higher public-charging percentage before assuming an EV saves money on energy.
What this doesn't include
- The upfront price gap between the EV and a comparable gas vehicle.
- Maintenance differences (typically lower for EVs, but not zero).
- Federal, state, or utility incentives.
- Resale-value differences.
Use the EV vs Gas Cost Calculator to fold those in. For multi-vehicle scenarios use the Fleet TCO model. If you're choosing between gas and diesel instead, see the gas vs. diesel comparison.
About these numbers
U.S. residential electricity averages and gasoline averages from EIA. Public charging prices reflect public network published rates and vary widely by state, network, and session length. Treat any per-mile number as a planning estimate — verify against your own utility bill and recent receipts.
