Electric Car Savings Calculator
Electric cars usually cost less to fuel per mile than petrol cars, but how much you save depends on your electricity rate, your fuel price, and how each vehicle performs. This calculator computes the cost per mile for an EV (efficiency in kWh per mile times your electricity price) and for a gas car (fuel price divided by miles per gallon), multiplies both by your annual mileage, and reports the yearly energy cost of each and the savings from going electric, all from figures you enter.
EV savings formula
EV cost per mile = EV efficiency (kWh/mile) * electricity price
Gas cost per mile = gas price / miles per gallon
EV annual cost = EV cost per mile * annual miles
Gas annual cost = gas cost per mile * annual miles
Annual savings = gas annual cost - EV annual cost
Each vehicle's cost per mile is computed from your prices and efficiencies, then scaled by annual miles. The savings is the gas annual cost minus the EV annual cost. A positive result means the EV is cheaper to fuel.
Electric vehicle context
- The US EPA and Department of Energy publish EV efficiency ratings at fueleconomy.gov.
- The US Energy Information Administration reports average residential electricity rates by state.
- EV efficiency is often quoted as kWh per 100 miles; divide by 100 for kWh per mile.
- This comparison covers energy cost only, not purchase price, incentives or maintenance.
- Overnight or time-of-use charging can lower the effective electricity rate.
Electric car savings: frequently asked questions
How does an EV's energy cost compare to gas?
An EV's cost per mile is its efficiency in kilowatt-hours per mile times your electricity price per kWh. A gas car's cost per mile is the fuel price per gallon divided by its miles per gallon. Multiply each by your annual miles and subtract to find the yearly savings. This calculator uses your own prices and efficiencies.
What is a typical EV efficiency?
EV efficiency is often quoted as miles per kWh or kWh per 100 miles. Many EVs use roughly 0.25 to 0.35 kWh per mile. The US EPA publishes ratings at fueleconomy.gov. Enter your vehicle's figure so the comparison reflects your actual EV rather than an assumption.
What electricity price should I use?
Use your home electricity rate per kilowatt-hour from your utility bill. The US Energy Information Administration publishes average residential rates by state. Time-of-use plans and overnight charging can lower the effective rate, so enter the rate you actually pay when charging.
Does this include the purchase price difference?
No. This calculator compares running energy cost only, which is where EVs usually save. It does not include the vehicle purchase price, tax incentives, maintenance or insurance. Those vary widely, so it focuses on the energy-cost comparison you can compute precisely from prices.
Are EV maintenance costs lower?
EVs have fewer moving parts and no oil changes, which often lowers maintenance, but tyres, brakes and battery considerations still apply. Because these vary by vehicle and use, this tool reports energy savings only. Add your own maintenance estimates separately for a full total-cost comparison.
Official sources
- U.S. Department of Energy and EPA: Electric Vehicles.
- U.S. Energy Information Administration: Electric Power Monthly.
Reviewed by the CalculatorHub team, edited by James Graham, 16 June 2026. See our methodology.