What the animation shows
The animation and the step-by-step video above use your numbers. Here is the same walkthrough written out for the default example.
What you enter
- Miles driven per year: 12000 mi.
- EV efficiency: 3.5 mi/kWh. Many EVs achieve 3–4 mi/kWh. 100 ÷ (kWh per 100 mi) converts.
- Charging efficiency: 90 %.
- Electricity rate: 0.15 $/kWh. Find this on your utility bill: total charges ÷ kWh used gives an all-in rate.
- Gas vehicle fuel economy: 30 mpg.
- Gasoline price: 3.5 $/gal.
What happens, step by step
- Both cars drive the same 12,000 miles over one year.
- The EV buys kWh at $0.15, losing 10% while charging.
- The gas car burns a gallon every 30 miles at $3.50.
- Per mile, electric costs $0.048 and gas $0.117.
The answer: yearly savings with the ev is $828.57.
How it’s calculated
- EV cost = miles ÷ mi/kWh ÷ charging efficiency × rate
- Gas cost = miles ÷ mpg × gas price
Worked example
12,000 miles, EV at 3.5 mi/kWh with 90% charging efficiency at $0.15/kWh, versus a 30 mpg car at $3.50/gal.
Inputs
- Miles driven per year
- 12000 mi
- EV efficiency
- 3.5 mi/kWh
- Charging efficiency
- 90 %
- Electricity rate
- 0.15 $/kWh
- Gas vehicle fuel economy
- 30 mpg
- Gasoline price
- 3.5 $/gal
Results
- Yearly savings with the EV
- $828.57
- EV yearly energy cost
- $571.43
- Gas yearly fuel cost
- $1,400.00
- EV cost per mile
- 0.048 $
- Gas cost per mile
- 0.117 $
Assumptions and limits
- All EV charging is at the home rate you entered; public fast charging usually costs more.
Verify the result against the applicable local code, adopted code edition, manufacturer instructions and project requirements. See our methodology.
Questions
Is it cheaper to charge an EV than buy gas?
With home charging at typical US rates, usually yes. The gap shrinks with expensive electricity or public fast charging.
How do I convert kWh/100 mi to mi/kWh?
Divide 100 by the kWh per 100 miles. 28 kWh/100 mi equals about 3.6 mi/kWh.