What this calculator does
The VinFast EV vs Gas Savings Calculator estimates how much money you can save each year by driving an electric vehicle, such as a VinFast model, instead of a comparable gasoline car. It compares the cost of buying gasoline with the cost of charging an EV based on your real driving habits and local energy prices. Prices and units are entered in US dollars, gallons, miles and kWh.
How to use it
Enter your annual miles driven, the fuel economy (MPG) of the gas car you are comparing against, your local gas price per gallon, the EV's energy consumption in kWh per mile (most EVs use about 0.25–0.35 kWh/mile), and your electricity price per kWh. The calculator returns your annual savings along with monthly and 5-year totals.
The formula explained
Gas cost is the miles you drive divided by MPG (giving gallons used) times the gas price. EV cost is miles times consumption (giving total kWh) times the electricity price. Annual savings is simply the gas cost minus the EV cost:
$$\text{Savings} = \frac{\text{miles}}{\text{MPG}} \times \text{gas\_price} - (\text{miles} \times \text{kWh/mile}) \times \text{price\_per\_kWh}$$
Worked example
Suppose you drive 12,000 miles a year. A gas car gets 28 MPG and gas costs $3.50/gallon: that's \((12000 \div 28) \times 3.50 = \$1{,}500\) per year. An EV using 0.30 kWh/mile at $0.15/kWh costs \(12000 \times 0.30 \times 0.15 = \$540\). Your annual savings $$= 1500 - 540 = \mathbf{\$960},$$ or about $80/month and $4,800 over five years.
FAQ
Does this include the purchase price difference? No — it compares only fuel/energy operating costs. EVs may also save on maintenance.
What consumption value should I use? Check your EV's rated efficiency; 0.25–0.35 kWh/mile is typical for most electric cars.
What if my gas car is more efficient than the EV is cheap to charge? If the EV cost exceeds the gas cost the savings will be negative, meaning gas would be cheaper at those prices.
