What is fleet utilization?
Fleet utilization is the share of a vehicle's available time or capacity that is actually used. A van that works 11 of 22 working days has a utilization of 50% by days. The same idea works with engine hours against the hours of a shift, or with distance against what a fully used vehicle of that type covers.
This fleet utilization calculator works out use per vehicle, flags vehicles that are under-used or close to their limit, and estimates how many vehicles the same work needs at your target utilization. Its second tab measures equipment idle hours: hours with the engine running but no work done, and what they cost in fuel and maintenance.
Why fleet utilization matters
- Every vehicle carries fixed cost. Depreciation or lease, insurance and licenses are paid whether it moves or not, so a parked vehicle has a high cost per day of use.
- Right-sizing frees capital. If the work fits on fewer vehicles, the surplus can be sold, returned or moved to a site that is short.
- Near-capacity vehicles are a risk. A vehicle used every working day has no slack for maintenance or a busy week.
- Idle hours are hidden cost. Equipment running without working burns fuel and adds engine hours, which bring the next service forward.
What data do you need to calculate fleet utilization?
| Input | Where to find it | Tip |
|---|---|---|
| Days used per vehicle | Trip reports, logbooks, booking records | Count a day as used when the vehicle made at least one working trip. |
| Engine hours | Hour meters, engine data, activity reports | Use the same period for every vehicle. |
| Distance | Odometer readings or trip reports | Set the full-use distance from your busiest vehicles of the same type. |
| Busiest day | Dispatch records | The most vehicles out at the same time sets the minimum fleet size. |
| Working versus idle hours | Hour meter versus work records, or engine activity data | Working hours are hours actually lifting, digging, pumping or driving. |
How to calculate fleet utilization and vehicles needed
Utilization per vehicle
Fleet average and vehicles needed
If you enter the number of vehicles out on the busiest day, the fleet size is never set below it.
Equipment idle hours
Worked example: 6 vehicles and 8 machines
Six vehicles had 22 working days in a month. They were used 20, 9, 21, 14, 6 and 17 days: 87 days in total.
- Fleet utilization is 87 ÷ (22 × 6) = 66%. Two vehicles are under 50% (27% and 41%), and two are at 90% or more.
- At a target of 80%, each vehicle offers 22 × 0.8 = 17.6 days, so the work needs 87 ÷ 17.6 = 4.9, rounded up to 5 vehicles. One vehicle is surplus.
- With a fixed cost of 9,000 a year per vehicle, the surplus vehicle costs about 9,000 a year to keep, and the other five would run at 79%.
- Eight machines run 160 engine hours a month but work 100: 60 idle hours, or 38%. At 3 L an hour, fuel at 1.10 and maintenance at 4.00 per engine hour, idling costs 7.30 an hour, or 42,048 a year. Bringing idle down to 20% of engine hours would save about 24,528 a year.
How to read your results before right-sizing
- Under-used vehicles are the first candidates to share between teams, move to another site or remove from the fleet.
- Near-capacity vehicles may need a spare or a booking rule, especially if they are also due for service.
- Vehicles needed is a planning figure. Check it against your busiest days and the jobs that need a specific vehicle type.
- Idle share above about a third of engine hours is usually worth a closer look at shift patterns, waiting time and operator habits.
Common mistakes in measuring utilization
- Counting calendar days. Measure against the days the vehicle could have worked, not every day in the month.
- Mixing vehicle types. A crane truck and a pool car are not interchangeable. Run the calculator per type.
- Sizing to the average. A fleet sized to the average day falls short on the busiest day. Enter your peak.
- Treating idle hours as free. They cost fuel and bring services forward, even if the machine is not moving.
- Using one month. Seasonal work can make a vehicle look surplus in one month and essential in another.
Assumptions and limits
Results are estimates based on the values entered. Vehicles needed assumes work can be shared between vehicles of the same type; it does not plan routes, shifts or locations. Idle cost uses the fuel rate and maintenance cost you enter and does not include operator wages. Validate any reduction in fleet size with dispatch records over several months before acting on it.