This calculator measures charger utilization for a fleet depot by comparing active charging hours with total charger availability. It also reports average sessions per charger, energy delivered per active hour, and the spare capacity left in the reporting window.
Fleet operators can use these measures to evaluate whether installed chargers are sufficient, whether schedules are balanced, or whether additional vehicles can be supported. Average utilization can hide short peak periods, so operational decisions should also consider arrival patterns, dispatch deadlines, load-management limits, and charger downtime.
1. Enter installed chargers
Count chargers available to fleet vehicles.
2. Set the reporting period
Use a consistent number of operating days.
3. Enter daily availability
Use the number of hours each charger can serve vehicles.
4. Add active charging hours
Sum time when chargers were delivering energy.
5. Add sessions and energy
These totals support turnover and power-context metrics.
6. Review capacity use
Compare utilization and unused charger-hours with fleet needs.
Available charger-hours = Chargers × Days × Available hours per day
Utilization (%) = Active charging hours ÷ Available charger-hours × 100
Unused charger-hours = Available charger-hours − Active charging hours
Sessions per charger = Sessions ÷ Chargers
Energy per active hour = Energy delivered ÷ Active charging hours
The main result is the percentage of scheduled charger availability used for active charging.
Connection time without energy flow is excluded unless it is included in the active-hours input.
Given: 12 chargers, 30 days, 12 available hours per day, 2,700 active charging hours, 900 sessions, and 36,000 kWh delivered.
Calculation: Available hours = 12 × 30 × 12 = 4,320 charger-hours. Utilization = 2,700 ÷ 4,320 × 100 = 62.5%. Unused hours = 4,320 − 2,700 = 1,620. Sessions per charger = 900 ÷ 12 = 75.
Result: Fleet charger utilization is 62.5%.
Average delivered energy per active hour is 36,000 ÷ 2,700 = 13.33 kWh.
Not for active charging utilization. Include it only if your operating definition treats connector occupancy as utilization.
Yes, because the denominator uses each depot’s available hours. Make sure availability and active time are defined consistently.
It is arithmetic spare capacity within the stated schedule, not guaranteed capacity at the exact hours vehicles need to charge.
Load management may keep chargers connected while reducing power. Time utilization can stay high even when energy throughput is constrained.
Not by itself. Check peak-hour conflicts, missed charging deadlines, downtime, and expected fleet growth before expanding.