EV vs gas savings calculator

How to Accurately Compare EV Electricity vs Gasoline Costs

When prospective car buyers consider switching from an internal combustion engine (ICE) vehicle to a battery electric vehicle (BEV), fuel savings is consistently cited as the primary economic motivator. However, assuming that driving an electric vehicle costs "almost nothing" is an oversimplification.

Accurately evaluating fuel economics requires converting gallons of gasoline and kilowatt-hours (kWh) of electricity into standardized cents per mile driven.

The Cost per Mile Formula

For a gasoline vehicle: $$\text{Cost Per Mile (Gas)} = \frac{\text{Gas Price per Gallon}}{\text{Vehicle MPG}}$$

At $3.60 per gallon and 28 MPG: $$\frac{$3.60}{28} = $0.128 \text{ (12.8 cents per mile)}$$

For an electric vehicle: $$\text{Cost Per Mile (EV)} = \frac{\text{Electricity Rate per kWh}}{\text{Vehicle Efficiency (Miles per kWh)}}$$

At the US residential average of $0.16 per kWh and an EV efficiency of 3.5 miles per kWh: $$\frac{$0.16}{3.5} = $0.045 \text{ (4.5 cents per mile)}$$

Under home charging conditions, the EV travels nearly three times as far per dollar spent on fuel.

The Impact of Commercial Fast Charging

Fuel savings compress significantly if a driver relies primarily on public commercial DC Fast Chargers (such as Tesla Superchargers, Electrify America, or EVgo).

While residential electricity averages $0.16 per kWh, commercial fast charging stations typically bill $0.38 to $0.52 per kWh:

• At $0.45 per kWh, an EV operating at 3.2 miles/kWh costs $0.14 per mile — virtually identical to a 32-MPG hybrid vehicle.
• To maximize EV financial return on investment, homeowners should install a dedicated Level 2 240V home charging station to capture off-peak residential utility rates.