What This Calculator Does
The VinFast Monthly Charging Budget Calculator estimates how much it costs to charge your electric vehicle at home each month. By combining your monthly driving distance, your car's energy efficiency, and your local electricity rate, it produces a realistic monthly budget figure plus yearly cost and cost-per-mile breakdowns. While built with VinFast EV owners in mind, the math applies to any electric vehicle.
How to Use It
Enter the number of miles you drive in a typical month, your vehicle's efficiency in miles per kWh, and the price you pay for electricity in dollars per kWh. Efficiency for the VinFast VF 8 and similar SUVs is often around 2.5–3.5 mi/kWh, while smaller EVs can exceed 4 mi/kWh. You can find your electricity rate on your utility bill. Click calculate to see your estimated monthly charging cost.
The Formula Explained
First, energy used is miles divided by efficiency: more efficient cars use fewer kWh per mile. Then cost is that energy multiplied by your per-kWh rate:
$$\text{Monthly Cost} = \frac{\text{Monthly Miles}}{\text{Efficiency}} \times \text{Rate}$$
Cost per mile is simply the monthly cost divided by the miles you drove, and yearly cost multiplies the monthly figure by 12.
Worked Example
Suppose you drive 1,000 miles per month, your VinFast gets 3.5 miles per kWh, and you pay $0.15 per kWh. Energy used = \(1000 \div 3.5 \approx 285.71\) kWh. Monthly cost = \(285.71 \times \$0.15 \approx\) $42.86. Cost per mile ≈ $0.043, and yearly cost ≈ $514.29.
FAQ
Does this include public DC fast charging? No — it assumes a single flat electricity rate, ideal for home charging. Public fast charging usually costs more per kWh.
What efficiency should I enter? Use your car's trip-computer average (mi/kWh). If you only know kWh/100 mi, divide 100 by that number.
Why is my real bill higher? Home charging has small energy losses (5–15%) and rates can vary by time of day; consider lowering your effective efficiency slightly for a conservative estimate.
