What this calculator does
The Electric vs Gas Car Cost Calculator compares the per-mile fuel cost of a gasoline vehicle with the per-mile energy cost of an electric vehicle (EV), then projects how much you would save (or lose) over a year of driving. It is jurisdiction-neutral — just enter prices in your own currency and units (US gallons and dollars are used in the labels, but any consistent currency works).
How to use it
Enter four numbers about your gas car and your EV: the price of gasoline per gallon, the car's fuel economy in MPG, your electricity rate in $/kWh, and the EV's efficiency in kWh per mile (typical EVs use 0.25–0.35 kWh/mile). Add your annual mileage and the calculator returns the cost per mile for each option plus the total yearly savings.
The formula explained
Gas cost per mile is the fuel price divided by miles per gallon: $$\text{GasCPM} = \frac{\text{GasPrice}}{\text{MPG}}$$ EV cost per mile is the energy consumed each mile times the electricity rate: $$\text{EVCPM} = \text{kWh/mile} \times \text{ElecPrice}$$ The annual savings is the difference multiplied by miles driven: $$(\text{GasCPM} - \text{EVCPM}) \times \text{Miles}$$ A positive result means the EV is cheaper to fuel.
Worked example
Suppose gas is $3.50/gallon at 30 MPG, electricity is $0.15/kWh, the EV uses 0.30 kWh/mile, and you drive 12,000 miles. Gas CPM = \(3.50 \div 30 = \$0.1167\). EV CPM = \(0.30 \times 0.15 = \$0.045\). Savings per mile = \(\$0.0717\), so annual savings = $$\$0.0717 \times 12{,}000 \approx \$860$$
FAQ
Does this include the car's purchase price? No — it compares fuel/energy operating cost only. Total cost of ownership also depends on price, depreciation, maintenance and incentives.
What if my EV efficiency is shown in miles per kWh? Convert it: \(\text{kWh/mile} = 1 \div (\text{miles per kWh})\). For example \(3.5 \text{ mi/kWh} = 0.286 \text{ kWh/mile}\).
Why is my savings negative? If electricity is expensive or gas is very cheap, the gas car can cost less per mile, producing a negative (unfavorable) savings figure.
