15 Fleet Management KPIs With Formulas: Utilization, Cost per Mile, Uptime and More

Fleet management KPIs are the numbers that tell you whether your vehicles and equipment are used well, maintained well and run at a sensible cost. The hard part is not choosing KPIs. It is making sure everyone calculates them the same way.

This guide defines 15 KPIs. For each one you get the formula, the data you need, and how to read the result. At the end, we show how to turn them into a dashboard.

How to Use This List

Three rules make fleet KPIs useful:

1. One formula per KPI, written down. "Utilization" means nothing until you define available time.
2. Automatic inputs. Pull hours, miles and fuel from telematics, and costs from maintenance and accounting records. Hand-typed numbers drift.
3. Compare like with like. Compare an asset with its own history and with similar assets before you compare it with industry averages.

Utilization KPIs

1. Fleet utilization rate

Formula: Utilization rate (%) = Hours in use ÷ Hours available × 100

Data: Engine hours or trip time from telematics. Available hours from your working calendar.

Utilization is the KPI most fleets get wrong, because "available" is vague. Pick one definition, such as scheduled shift hours excluding planned maintenance, and apply it to every asset.

For road vehicles you can measure utilization in days used or miles driven instead of hours. For heavy equipment, use engine hours.

How to read it: Low utilization across a group of similar assets suggests you own too many. High utilization on a few assets suggests uneven allocation, and those assets will wear out first.

2. Idle time percentage

Formula: Idle time (%) = Idle hours ÷ Engine hours × 100

Data: Idle hours and engine hours from telematics. Heavy equipment reports both through the ISO 15143-3 standard.

Idling burns fuel and adds engine hours without doing work. That means earlier services and lower resale value.

3. Asset availability (uptime)

Formula: Availability (%) = (Scheduled hours − Downtime hours) ÷ Scheduled hours × 100

Data: Downtime from work orders, scheduled hours from your operating calendar.

Availability tells you whether assets are ready when you need them. Track planned and unplanned downtime separately.

Cost KPIs

4. Cost per mile or per engine hour

Formula: Cost per mile = Total operating cost ÷ Miles driven For equipment: Cost per engine hour = Total operating cost ÷ Engine hours

Data: Fuel, maintenance, repairs, tyres, insurance and depreciation or lease costs from accounting and maintenance records. Miles or hours from telematics.

Decide whether to include driver wages, and say so on the report. The American Transportation Research Institute publishes an annual analysis of trucking operating costs, which is a useful reference point for US truck fleets.

5. Fuel cost per mile

Formula: Fuel cost per mile = Fuel spend ÷ Miles driven

Data: Fuel card transactions and telematics mileage.

This separates fuel from other costs, so you can see the effect of routes, idling and driver behaviour.

6. Fuel economy

Formula: Miles per gallon = Miles driven ÷ Gallons used For equipment: Fuel per engine hour = Fuel used ÷ Engine hours

Data: Telematics fuel data or fuel card transactions matched to vehicles.

Compare each asset against others of the same model and duty. A sudden drop can point to a mechanical problem.

7. Maintenance cost per asset

Formula: Maintenance cost per asset = Parts + labour + outside repair costs for the asset ÷ period

Data: Work orders and invoices.

Rising maintenance cost is often the earliest signal that an asset is approaching replacement.

8. Total cost of ownership

Formula: TCO = Purchase or lease cost + Operating costs + Maintenance costs − Resale value

Data: Finance records over the asset's life.

TCO drives replacement decisions. Compare it per mile or per engine hour across asset types.

Maintenance KPIs

9. Preventive maintenance compliance

Formula: PM compliance (%) = Preventive services completed on time ÷ Preventive services due × 100

Data: Maintenance schedule and work order completion dates.

This is the single best leading indicator of fleet health. Many fleets target above 90%. US motor carriers must also systematically inspect, repair and maintain their vehicles under federal rules.

10. Planned vs unplanned maintenance ratio

Formula: Planned ratio (%) = Planned maintenance hours ÷ Total maintenance hours × 100

Data: Work orders tagged as planned or unplanned.

Unplanned work costs more and causes downtime. A rising unplanned share means your preventive programme is not working.

11. Mean time between failures (MTBF)

Formula: MTBF = Total operating hours ÷ Number of failures

Data: Engine hours from telematics and breakdown work orders.

Higher is better. Track MTBF by model to spot unreliable equipment types.

12. Mean time to repair (MTTR)

Formula: MTTR = Total repair time ÷ Number of repairs

Data: Work order open and close times.

Lower is better. A high MTTR often points to parts availability or technician capacity, not the asset itself.

13. Inspection defect closure time

Formula: Average closure time = Sum of (defect closed time − defect reported time) ÷ Number of defects

Data: Digital inspection reports and linked work orders.

Driver vehicle inspection reports are a federal requirement for many US commercial vehicles. Fast closure of reported defects is both a safety and a compliance measure.

Safety KPIs

14. Accident rate

Formula: Accident rate = Number of accidents ÷ Miles driven × 1,000,000

Data: Incident reports and telematics mileage.

Expressing accidents per million miles lets you compare fleets and periods of different sizes.

15. Harsh event rate

Formula: Harsh events per 1,000 miles = Harsh braking, acceleration and cornering events ÷ Miles driven × 1,000

Data: Telematics event data.

This is a leading indicator for accidents, fuel waste and wear on brakes and tyres.

Fleet KPI Summary Table

KPI	Formula	Main data source
Utilization rate	Hours used ÷ hours available × 100	Telematics
Idle time	Idle hours ÷ engine hours × 100	Telematics
Availability	(Scheduled − downtime) ÷ scheduled × 100	Work orders
Cost per mile or hour	Operating cost ÷ miles or hours	Accounting + telematics
Fuel cost per mile	Fuel spend ÷ miles	Fuel cards + telematics
Fuel economy	Miles ÷ gallons	Telematics or fuel cards
Maintenance cost per asset	Parts + labour + outside repairs	Work orders
Total cost of ownership	Purchase + operating + maintenance − resale	Finance
PM compliance	On-time PMs ÷ PMs due × 100	Maintenance schedule
Planned ratio	Planned hours ÷ total maintenance hours × 100	Work orders
MTBF	Operating hours ÷ failures	Telematics + work orders
MTTR	Repair time ÷ repairs	Work orders
Defect closure time	Average of closed − reported time	Inspections
Accident rate	Accidents ÷ miles × 1,000,000	Incidents + telematics
Harsh event rate	Events ÷ miles × 1,000	Telematics

Building a Fleet KPI Dashboard

A dashboard should answer three questions at a glance: are assets working, are they healthy, and what do they cost?

• Top row: utilization, availability and cost per mile or hour, each with a trend line.
• Second row: PM compliance, open work orders and overdue inspections.
• Drill-down: every number should click through to the assets behind it.
• Alerts: notify people when a KPI crosses a threshold, rather than waiting for the monthly report.

The main technical work is joining data. Telematics, maintenance, fuel cards and accounting usually live in different systems. A shared asset ID, such as VIN or PIN, is what makes the joins reliable.

Where Ortem Can Help

Ortem builds fleet platforms and data layers that calculate these KPIs automatically from telematics, maintenance and finance data. See our fleet management software development services and our Fleet Sync Pro product. For construction fleets, read our guide to construction fleet management software.