- Enter delivered energy. Use the energy stored in vehicles on an average operating day.
- Enter electricity price. Use the blended price applicable to the charging window.
- Set charging efficiency. Account for conversion and thermal losses between the grid and battery.
- Add fixed daily charges. Include a daily allocation of demand, service, network, or site charges when appropriate.
- Choose operating days. Use the period you want to budget.
- Review total and unit cost. Compare purchased grid energy, variable cost, and cost per delivered kilowatt-hour.
Fleet Electrification Energy Cost Estimator
This calculator estimates fleet charging energy cost over a selected period. It combines delivered energy, electricity price, charging losses, demand or service charges, and the number of operating days. The result includes total grid energy, variable electricity cost, fixed charges, and average cost per delivered kilowatt-hour.
The calculator is useful for budgets, route economics, station pricing, and scenario comparisons. It does not reproduce every utility tariff; time-of-use blocks, demand ratchets, taxes, network fees, and subscription structures may require a more detailed billing model.
Calculator inputs
kWh
$/kWh
%
$
days
Result
—
Calculated result
Grid energy purchased—
Variable energy cost—
Cost per delivered kWh—
Grid energy = Delivered energy ÷ Charging efficiency × Operating days
Variable cost = Grid energy × Electricity price
Total cost = Variable cost + (Daily fixed charge × Operating days)
Cost per delivered kWh = Total cost ÷ Total delivered energy
Enter efficiency as a percentage; 91% is used as 0.91. Fixed charges are modeled as a simple daily amount.
What the result means
Use the result to compare scenarios under the assumptions entered. It is an estimate, not a guaranteed real-world outcome.
Update the inputs with measured vehicle, charger, tariff, and operating data whenever available.
Given: 850 kWh delivered per day, $0.18/kWh electricity, 91% efficiency, $35 in daily fixed charges, and 30 operating days.
Calculation: Grid energy = 850 ÷ 0.91 × 30 = 28,021.98 kWh. Variable cost = 28,021.98 × $0.18 = $5,043.96. Fixed cost = $35 × 30 = $1,050. Total = $6,093.96. Delivered energy = 25,500 kWh, so unit cost = $0.239/kWh.
Result: Estimated 30-day fleet charging cost is $6,093.96.
Why is grid energy higher than delivered energy?
Charging equipment and batteries lose some energy as heat and through conversion. Dividing by efficiency estimates the electricity that must be purchased to deliver the target energy.
Should I use the cheapest advertised electricity rate?
Use the effective rate during charging hours, including time-of-use differences when known. A blended historical rate may be more representative.
How should demand charges be entered?
Convert the expected billing-period demand charge and other fixed fees into an average daily allocation. For exact tariff modeling, calculate those charges separately.
Can the result be used to set charging prices?
It can provide an energy-cost baseline, but pricing may also need to cover equipment, maintenance, parking, payment processing, taxes, and profit margin.
What if no energy is delivered?
The calculator can still show fixed charges, while cost per delivered kilowatt-hour is displayed as zero because there is no delivered-energy denominator.