About the EV vs Gas Cost
The EV vs Gas Car Cost Calculator compares what you would spend each year fueling a gasoline car against charging an electric vehicle for the same amount of driving. It lets you weigh a specific gas price and electricity rate against your own annual mileage rather than relying on a generic national average, which is useful when you're deciding between a gas and electric replacement for your next vehicle.
How It Works
You enter your annual miles driven, the price of gas, your gas car's fuel economy in miles per gallon, your local electricity rate, and the EV's efficiency in kWh per 100 miles. The calculator works out the gallons a gas car would burn over that mileage and multiplies by gas price, then works out the kWh an EV would draw over the same mileage and multiplies by your electricity rate. The difference between the two is your estimated annual savings from driving electric.
Examples
Daily commuter at national averages
Driving 12,000 miles a year in a 28 mpg gas car at $3.50 a gallon costs about $1,500 in fuel. Charging an EV rated at 30 kWh per 100 miles at $0.16 a kWh for the same 12,000 miles costs about $576, a savings of roughly $924 a year.
Higher mileage, pricier gas
A driver covering 15,000 miles a year in a 24 mpg car at $3.80 a gallon spends about $2,375 on gasoline. The same mileage in an EV using 28 kWh per 100 miles at $0.13 a kWh costs about $546, putting annual fuel savings near $1,829.
Advantages
- Uses your own gas price, electricity rate, and mileage instead of a generic published average, so the result reflects your actual driving and local utility costs.
- Separates fuel cost from purchase price, making it easy to isolate the ongoing running-cost question from the upfront cost-of-ownership question.
- Lets you test how sensitive the comparison is to gas price swings or electricity rate changes by adjusting one input at a time.
Common Mistakes
- Comparing sticker MPG to sticker kWh/100mi without adjusting either for real-world driving conditions, which can shift both numbers in either direction.
- Ignoring that EV efficiency worsens meaningfully in cold weather or with heavy highway driving, which can push the true kWh/100mi figure higher than the vehicle's rated efficiency.
- Treating the annual fuel savings figure as the full financial case for switching to an EV, when purchase price, incentives, and maintenance costs also matter.
Edge Cases to Watch For
- mpg is floored at 1 in the calculation, so entering 0 or a negative fuel economy value doesn't produce a divide-by-zero error, though the resulting gas cost figure would no longer be realistic.
- The comparison only covers fuel and charging cost per mile; it does not account for the purchase price gap between EV and gas models, insurance, maintenance, or the fact that most EV charging happens at home overnight while some gas cars are driven only on weekends.
- Electricity rates that increase with usage on tiered residential plans, or a mix of home and public charging at different price points, aren't reflected, since the calculator applies one flat rate.
Common Use Cases
- Shoppers cross-shopping a specific EV and gas model who want a same-mileage, same-price fuel comparison before deciding.
- Current EV owners estimating how much they're saving on fuel compared to their previous gas vehicle.
- Anyone budgeting for a household's annual transportation costs under either vehicle type.