This calculator estimates charger utilization when tire-related efficiency losses increase the energy demand of an EV fleet or repeated charging operation. It converts vehicle activity into charger-hours and compares those hours with available charger capacity.
Fleet operators, workplaces, and property managers can use the result to test whether a tire setup or pressure issue meaningfully affects charging congestion. The calculation assumes an average charging power and an even planning period.
1. Enter fleet activity
Add vehicle count and average daily miles per vehicle.
2. Set baseline efficiency
Use a representative miles-per-kWh value before the tire penalty.
3. Describe the tire effect
Enter the percentage reduction in driving efficiency.
4. Add charging capacity
Enter average delivered power, charger count, and hours available per charger.
5. Review utilization
A result above 100% means the modeled daily demand exceeds the stated charger-hour capacity.
This simplified model treats charger power and fleet demand as averages and excludes queue timing.
The headline shows the share of available charger-hours needed to supply the modeled daily driving energy.
A feasible utilization percentage does not guarantee that every vehicle can charge on schedule; arrival overlap and charging curves also matter.
Given: 20 vehicles, 60 miles each, 3.2 mi/kWh, 5% tire penalty, five 9.6 kW chargers, and 12 available hours.
Calculation: Adjusted energy = 20 × 60 / 3.2 / 0.95 = 394.74 kWh. Required charger-hours = 394.74 / 9.6 = 41.12 hours. Available capacity = 5 × 12 = 60 charger-hours.
Result: Estimated utilization is 68.5%, versus 65.1% without the tire penalty.
Not exactly. This model calculates energy-based charger-hours; actual plug occupancy can be longer because vehicles may remain connected after charging.
This version focuses on tire-driven vehicle energy. You can reduce the entered average delivered power to represent system losses conservatively.
The stated chargers and available hours cannot deliver the modeled energy at the entered average power.
Yes. Persistent underinflation can increase rolling resistance and daily energy use.
Compare scenarios for charger count, charging window, tire maintenance, and route mileage before committing to infrastructure changes.