What this calculator does
The VinFast VF8 Charging Cost Calculator estimates how much it costs to charge your VinFast VF8 electric SUV at home or a public charger. It accounts for the battery capacity, the start and target state of charge, your electricity price, and real-world charging efficiency (energy lost as heat during charging).
How to use it
Enter your VF8 battery capacity (the VF8 Plus uses an 87.7 kWh pack), your electricity price per kWh, the current charge level, the target charge level, and the charging efficiency. Most home AC charging is around 85–92% efficient. The calculator returns the estimated cost plus the energy added to the battery and the energy actually drawn from the grid.
The formula explained
First, the energy added to the battery is the capacity times the percentage gained: \(C \times (T - S) / 100\). Because charging is not perfectly efficient, the grid must supply more than that: divide by the efficiency \(\eta\). Finally multiply the grid energy by your price per kWh to get the cost.
$$\text{Cost} = \frac{\text{Battery (kWh)} \times \dfrac{\text{Target \%} - \text{Start \%}}{100}}{\dfrac{\text{Efficiency \%}}{100}} \times \text{Price (\$/kWh)}$$
Worked example
An 87.7 kWh VF8 Plus charged from 20% to 80% gains 60% of 87.7 = 52.62 kWh into the battery. At 90% efficiency the grid supplies 52.62 / 0.9 = 58.47 kWh. At $0.16/kWh the cost is 58.47 × 0.16 ≈ $9.36.
$$\frac{87.7 \times \dfrac{80 - 20}{100}}{\dfrac{90}{100}} \times 0.16 = \frac{52.62}{0.9} \times 0.16 = 58.47 \times 0.16 \approx \$9.36$$
FAQ
Why is grid energy higher than battery energy? Charging loses energy as heat, so you pay for more kWh than what reaches the battery.
What efficiency should I use? Use ~90% for home AC charging; DC fast charging can be lower. Set 100% to ignore losses.
Does this work for the VF8 Eco? Yes—just change the battery capacity to match your trim.
