Costs
Maintenance cost per mile: calculating and using it
A repair bill tells you what one job cost. Maintenance cost per mile tells you what a vehicle costs to keep running, in a form you can compare across the fleet and over time. It is the number that shows which vehicle is quietly draining the budget, and when replacing it would cost less than keeping it.
The formula
For one vehicle, over one period:
Maintenance cost per mile = maintenance and repair costs in the period ÷ miles driven in the period
Miles driven is the odometer reading at the end of the period minus the reading at the start. Both parts must cover the same dates. A repair invoice that arrives after the period closes still belongs to the period in which the work was done, so a figure worked out on the first day of the month may change once late invoices arrive.
What to include
| Include | Notes |
|---|---|
| Parts | Everything fitted to the vehicle, including filters and fluids from planned service |
| Labor | In-house hours at a loaded hourly rate (wages plus benefits), so in-house and outside work compare fairly |
| Outside repairs | Dealer and vendor invoices, roadside repairs and towing |
| Tires | Replacement, repair and retreading; many fleets also report tires on their own line because they are a large, separate cost |
| Warranty recoveries | Subtract amounts recovered on claims, so a covered repair does not count against the vehicle; see fleet warranty claims |
Keep fuel separate. Fuel usually costs far more than maintenance and moves with fuel prices and routes. Mixed into one number, it hides what the vehicle itself costs. Track it as its own figure; see fuel economy and IFTA records. Insurance, depreciation, financing, licensing and driver pay belong in total cost of ownership, which is a different calculation.
Per engine hour, for equipment and idling vehicles
For machines without a meaningful odometer (forklifts, generators, yard tractors, construction equipment), and for trucks that spend long periods idling or running power take-off equipment, divide by engine hours instead:
Maintenance cost per engine hour = maintenance and repair costs in the period ÷ engine hours run in the period
Use one measure per vehicle group and keep to it. Comparing one truck's cost per mile with another's cost per hour compares nothing.
A worked example
The numbers below are invented round figures to show the method. They are not benchmarks.
| Truck 12 | Truck 17 | |
|---|---|---|
| Parts | $2,000 | $4,500 |
| Labor | $1,500 | $3,000 |
| Outside repairs | $500 | $2,500 |
| Warranty recovered | $0 | −$1,000 |
| Net maintenance cost | $4,000 | $9,000 |
| Odometer at start / end of period | 200,000 / 240,000 | 410,000 / 440,000 |
| Miles in period | 40,000 | 30,000 |
| Cost per mile | $0.10 | $0.30 |
Truck 17 costs three times as much per mile to maintain. Before acting on that, check whether the comparison is fair.
Comparing vehicles fairly
- Age and mileage. Maintenance cost generally rises as a vehicle ages. Compare a vehicle with others of similar age and mileage, and with its own earlier periods.
- Duty cycle. Stop-and-go delivery, construction sites and heavy loads cost more per mile than steady highway running. Group vehicles by the work they do.
- Period length. One large repair can dominate a single month. Look at a rolling twelve months as well as the latest period.
- One-off events. Accident damage is usually reported separately, because it says nothing about the vehicle's mechanical condition.
- Missing readings. If the odometer readings for the period are missing or doubtful, leave the figure blank. An estimated mileage produces a precise-looking number that is wrong.
When the numbers say replace
A common way to use cost per mile is to watch the trend for each vehicle. When a vehicle's maintenance cost per mile keeps rising, and the repairs are taking it off the road more often, compare what it will cost to keep for another year (expected maintenance, downtime, rental of a spare) with what a replacement would cost over the same year. There is no fixed figure at which a vehicle must be replaced; the decision depends on your duty cycle, financing, resale values and how much downtime your operation can absorb. What cost per mile does is turn that decision from a feeling into a comparison.
Records that make the number trustworthy
- Every repair has a work order tied to one vehicle, with parts, labor and outside costs on separate lines.
- Late invoices are added to the original job, not booked to the month they arrived.
- Odometer or hour readings are recorded regularly, so the miles for any period can be worked out.
- Corrections are recorded as corrections, so the history explains every change in the total.
Cargovate works out repair costs per vehicle, split into parts, labor, vendors and other, and divides them by the miles or engine hours the vehicle's own readings show, leaving the figure blank when the readings cannot tell. The same records support the maintenance file the rules require; for terms, see the glossary.
Last reviewed 2026-11-04