Short answer
Fleet maintenance cost per mile is what you spent on maintenance in a period divided by the miles driven in that period. Add parts, labour, outside shop invoices and tires for each truck, take the odometer reading at the start and end of the period, and divide. Work it out for each truck as well as for the fleet.
Key points
- Maintenance cost per mile = (parts + labour + outside shop invoices + tires) ÷ miles driven in the same period.
- Count your own shop’s labour at a loaded hourly rate, and keep fuel, accident repairs and upgrades out of the figure so it measures wear and tear.
- Take miles from odometer readings at the start and end of the period, and use a full year or at least a quarter so one big repair does not distort the number.
- Compare trucks of similar age and duty. A unit whose cost per mile keeps climbing is the first candidate for a repair-or-replace review.
The formula
For one truck over one period:
Total maintenance cost is parts, labour, outside shop invoices and tires for that unit. Miles driven is the odometer reading at the end of the period minus the reading at the start. Canadian fleets can run the same sum in kilometres; to convert a cost per kilometre to a cost per mile, multiply by 1.609.
For the whole fleet, add up every truck’s costs and divide by every truck’s miles. Do not average the per-truck figures: a low-mileage truck with a high cost per mile would pull a simple average far more than its share of the miles justifies. The worked example below shows the difference.
Pick a period long enough to smooth out lumpy repairs. A month is too short: one clutch job makes a truck look terrible for that month and cheap for the next eleven. A rolling 12 months is the most useful view, reviewed every quarter.
What to include and what to leave out
The goal is a number that measures what it costs to keep the truck running as it wears. Count everything the truck consumed in maintenance, whoever did the work, and keep out costs that come from somewhere else.
| Cost | Include? | Notes |
|---|---|---|
| Parts and shop supplies | Yes | Filters, fluids, lubricants, belts, brake parts and every part used on the unit |
| Your own shop’s labour | Yes | Hours on the unit times a loaded hourly rate: the technician’s wage plus payroll costs and benefits |
| Outside shop and dealer invoices | Yes | Including roadside repairs and towing after a breakdown |
| Tires, retreads and tire repairs | Yes | Often the largest single line; many fleets also track tire cost per mile on its own |
| PM services and periodic inspection fees | Yes | Scheduled work is part of the cost of keeping the truck on the road |
| Repairs covered by warranty | Record, at no cost | Keep the event in the history; it shows how often a component fails |
| Accident damage | Track separately | Collision repairs and insurance claims are not wear and would distort the trend |
| Fuel and DEF | No | Operating costs, measured in your overall cost per mile, not maintenance |
| Upgrades and added equipment | Usually no | Spending that improves the truck is closer to a capital cost; ask your accountant |
| Shop building, tools and overhead | Optional | Include it for a fully loaded figure, but do it the same way every period |
Whatever you decide, write the rules down and apply them every period. A cost per mile that changes because you changed what you count tells you nothing.
Where the numbers come from
You already keep most of the data. US rule 49 CFR 396.3 requires a record of the date and nature of every inspection, repair and maintenance job on each vehicle, and Canada’s NSC Standard 11 asks for the invoices and the odometer reading at every service or repair. If each work order and outside invoice is tied to a unit number, the cost side is a sum. See our guide to truck maintenance records for how to keep the file.
For miles, use odometer readings, not dispatch or loaded miles. Every mile wears the truck, including deadhead and trips to the shop. Your ELD or your fuel tax trip records usually hold the readings you need for the start and end of each period.
Worked example: three trucks, one year
A small fleet runs three highway tractors of different ages. Figures are in your own currency, and in-house labour is charged at a loaded rate of 65.00 an hour.
| Item | Truck 101 (2023) | Truck 102 (2020) | Truck 103 (2017) | Fleet |
|---|---|---|---|---|
| Parts | 4,200.00 | 7,900.00 | 12,600.00 | 24,700.00 |
| In-house labour (hours) | 2,600.00 (40) | 4,550.00 (70) | 7,150.00 (110) | 14,300.00 (220) |
| Outside shop invoices | 1,150.00 | 3,400.00 | 9,800.00 | 14,350.00 |
| Tires | 3,050.00 | 3,650.00 | 3,450.00 | 10,150.00 |
| Total maintenance cost | 11,000.00 | 19,500.00 | 33,000.00 | 63,500.00 |
| Odometer at start | 212,400 | 486,900 | 803,200 | |
| Odometer at end | 337,400 | 604,900 | 899,200 | |
| Miles driven | 125,000 | 118,000 | 96,000 | 339,000 |
| Maintenance cost per mile | 0.088 | 0.165 | 0.344 | 0.187 |
Truck 101 costs about 0.09 per mile to maintain, Truck 102 about 0.17 and Truck 103 about 0.34. The fleet figure is 63,500.00 divided by 339,000 miles, or about 0.19 per mile. A simple average of the three trucks would give 0.20, overstating the fleet because Truck 103 drove the fewest miles.
The table also shows where Truck 103’s money goes. Its outside shop bills are more than eight times Truck 101’s, which usually means breakdowns away from home: towing, road calls and repairs at whatever shop was nearest. That pattern matters as much as the total.
In kilometres, the fleet’s 0.187 per mile is about 0.116 per kilometre.
Cost per vehicle or cost per mile?
Both numbers are useful, for different questions.
- Cost per vehicle is the total maintenance spend on one unit for the period. It is the number for budgets and for comparing units that run similar miles. Truck 103 cost 33,000.00 to maintain, three times Truck 101.
- Cost per mile divides that by the miles the unit ran. It is the number for comparing units that run different miles, and for setting the maintenance part of your rates. Per mile, Truck 103 costs almost four times as much as Truck 101, because it cost more and ran fewer miles.
Watch low-mileage units. Time-based costs such as the periodic inspection and calendar PM spread over fewer miles, so a spare truck can look expensive per mile without anything being wrong. Compare like with like: same model and age band, same kind of work.
Trailers usually have no odometer, so most fleets compare them by cost per vehicle over the year, or by miles from a hubodometer where one is fitted.
What the industry figures say
The American Transportation Research Institute (ATRI) publishes the best-known benchmark, An Analysis of the Operational Costs of Trucking. Its 2026 update, released in July 2026, found that the industry-average cost to operate a truck in 2025 was 2.336 per mile, 3.4 percent higher than the year before and the highest in the report’s history. Excluding fuel, costs were 1.854 per mile. These are US carriers’ figures, in US currency.
Every major line item rose in 2025. Repair and maintenance had one of the largest increases, 8.6 percent, and tires rose 6.4 percent; only tolls rose faster than repair and maintenance. The full report, a free download from ATRI after a short form, breaks the costs down by line item and sector.
Use benchmarks for context, not as a target. They are averages of total operating cost across fleets of every size, sector and equipment age, and they may not count labour or overhead the way you do. Your own trend, truck by truck and quarter by quarter, tells you far more.
Using cost per mile to decide: repair or replace
Maintenance cost per mile rises as a truck ages, and at some point the repairs cost more than the payments on a newer unit. Cost per mile shows you when to run that comparison.
- Track each unit every quarter on a rolling 12 months, so the trend is visible before the big bill arrives.
- Compare with peers: units of the same model and age band. A truck well above its peers needs a closer look.
- List what is coming: overhauls, aftertreatment work, clutches, tires. Estimate next year’s maintenance and divide by the miles you expect.
- Add downtime. Count the days the unit was out of service and what those days cost you in lost loads or rented equipment.
- Compare with the replacement. Set the old truck’s expected maintenance and downtime against a newer unit’s lower maintenance plus its higher ownership cost.
In the example, the shop expects Truck 103 to need about 38,000.00 of work next year over 92,000 miles, or about 0.41 per mile. A truck like 101 runs about 0.09 per mile, so on the same miles the maintenance gap is close to 29,900.00, before counting the 21 days Truck 103 spent out of service last year. If that gap plus the lost days is more than the extra yearly cost of owning a newer truck, replacement wins.
Maintenance is only one line of the decision. Fuel, driver pay, insurance and the payment all change too, which is why many fleets look at it alongside the rest of the operation in TruckerPro’s fleet management software.
How RigMD shows maintenance costs
RigMD is the maintenance side of the TruckerPro TMS. On Pro, the maintenance costs report gives the cost for each truck and trailer from its work orders and outside-shop invoices, as a page, a CSV or a PDF. Where a shop invoice is linked to a work order, the report shows that overlap separately so you can see it.
Outside-shop invoices are recorded against the vehicle: an AI scan reads the receipt, and someone approves it. Each work order carries parts and labour totals. Labour comes from start and stop timers for each mechanic or from manual time entries, at each mechanic’s own hourly rate, and mechanics do not see costs.
RigMD reports cost per vehicle; cost per mile is the next step, and it is yours. Each truck has one current odometer reading, updated from a connected Motive, Samsara or Radical ELD through TruckerPro’s ELD integration, when a work order closes, or by hand. Note the reading at the start of each period, then divide the period’s cost by the miles driven. On Premium, tire tracking shows cost per mile for each tire.
Cost per vehicle, shop invoices with AI receipt scan and work order totals start on Pro. Compare the plans.
Sources
- New ATRI report details accelerating costs and low profitability despite cuts (2026 Analysis of the Operational Costs of Trucking), American Transportation Research Institute
- Analysis of the Operational Costs of Trucking: 2026 Update, American Transportation Research Institute
- 49 CFR 396.3 Inspection, repair, and maintenance, eCFR (FMCSA regulations)
- National Safety Code Standard 11: Maintenance and Periodic Inspection Standards, CCMTA
This guide is general information, not legal or engineering advice. Rules change and differ by jurisdiction; check the regulation or the agency named above, and your equipment maker’s service manual.