This estimator calculates the electricity cost of charging an EV fleet over a reporting period. It combines vehicle count, energy per vehicle, charging frequency, electricity rate, demand or service charges, and charging efficiency.
Fleet managers can use the output for operating budgets, route-cost comparisons, or evaluating charging schedules. The calculator reports total cost, cost per vehicle-charge, and cost per usable kilowatt-hour. It does not automatically model time-of-use intervals, demand peaks, or charger capital costs unless those amounts are entered through the additional charge field.
1. Enter fleet size
Count vehicles included in the monthly estimate.
2. Enter energy per charge
Use battery energy added during a typical charging event.
3. Set monthly frequency
Enter average charging events per vehicle.
4. Add the electricity rate
Use the blended energy rate or the applicable tariff rate.
5. Include fixed charges
Add monthly demand, service, or allocated site charges.
6. Set efficiency and review
Efficiency converts battery energy demand into grid energy purchased.
Monthly battery energy = Vehicles × Energy per charge × Charges per vehicle
Grid energy = Monthly battery energy ÷ Efficiency
Variable energy cost = Grid energy × Electricity rate
Total monthly cost = Variable energy cost + Monthly demand and service charges
Cost per vehicle-charge = Total monthly cost ÷ (Vehicles × Charges per vehicle)
The main result is the estimated recurring monthly electricity and site-charge cost for fleet charging.
Capital costs, maintenance, taxes, and non-electric operating costs are excluded unless entered in the fixed-charge field.
Given: 30 vehicles, 40 kWh per vehicle-charge, 20 charges per vehicle per month, $0.16/kWh, $1,200 fixed charges, and 90% efficiency.
Calculation: Battery energy = 30 × 40 × 20 = 24,000 kWh. Grid energy = 24,000 ÷ 0.90 = 26,666.67 kWh. Variable cost = 26,666.67 × $0.16 = $4,266.67. Total = $4,266.67 + $1,200 = $5,466.67.
Result: Cost per vehicle-charge = $5,466.67 ÷ 600 = $9.11.
The estimated monthly fleet charging cost is $5,466.67.
Enter battery energy added. The efficiency input converts that amount to grid energy purchased.
Use a weighted average rate or calculate each tariff period separately and combine the results.
Enter the monthly amount in the demand and service charges field. If demand charges vary, test multiple scenarios.
No, unless you intentionally add an allocated monthly amount to fixed charges. Keep that assumption documented.
Fixed charges are spread across the number of charging events. Fewer events make the fixed-cost portion per event larger.