What cost per mile includes
A useful tire cost-per-mile calculation includes the original casing cost, retread costs, mounting or service costs, repair costs, and any casing credit or residual value. The denominator is the total miles delivered by that tire position or casing lifecycle.
The method can be applied to steer, drive, trailer, regional, long-haul, vocational, or mixed fleets. Segmenting by position matters because steer tires, drive tires, and trailer tires have different wear patterns, failure risks, and retread policies.
- Original tire cost.
- Retread and repair cost.
- Service and mounting cost.
- Casing credit or disposal cost.
- Total miles before removal or failure.
How to calculate
Use the formula tire cost per mile = (casing cost + retread costs + service costs - casing credit) / total miles. If a tire costs $520, receives one $210 retread, has $40 of service cost, earns a $60 casing credit, and delivers 180,000 total miles, cost per mile = ($520 + $210 + $40 - $60) / 180,000 = $0.00394 per mile.
For a tractor with 18 tires, small differences become material. A tire program that saves 0.15 cents per tire mile can save $27 per 1,000 vehicle miles on an 18-tire combination, before fuel, downtime, and roadside-event effects.
Using the metric
Cost per mile is most useful when paired with removal reason. A low-cost tire that fails early on road calls may be worse than a more expensive tire that retreads reliably. Track tread depth at removal, irregular wear, punctures, run-flat damage, and casing rejection reasons.
The calculation also supports replacement forecasts. If a drive position averages 130,000 miles to pull and the unit runs 9,000 miles per month, the expected replacement interval is about 14.4 months. That helps schedule inventory and cash needs.
Common mistakes
Do not compare steer and trailer tires in one blended number unless you also keep position-level detail. Do not ignore casing credit; retreadable casings are an asset, and rejected casings are a cost signal.
Another mistake is using vehicle odometer miles when the tire moved between units without tracking install and removal readings. Tire history must follow the casing, not just the truck.
- Leaving out roadside service events.
- Counting retread miles without retread cost.
- Ignoring dual mismatch and inflation issues.
- Treating all removals as normal wear.
Who needs it
Fleet maintenance managers, tire program vendors, finance teams, and owner-operators use tire cost per mile to evaluate brands, retread strategies, inflation programs, and replacement timing. It is also useful when deciding whether to lease tires or own casings.
The best programs combine cost per mile with safety and downtime metrics. A narrow focus on purchase price can hide the real cost of premature removals and emergency service.
Frequently asked questions
Should retreads be included in tire cost per mile?
Yes. Retread costs and retread miles are part of the casing lifecycle and should be included when evaluating total tire economics.
How do I handle a tire moved to another truck?
Track install and removal odometer readings for each position and keep the history with the casing. Otherwise the mileage denominator will be wrong.
Is lower tire cost per mile always better?
Not always. A low cost per mile can still be unacceptable if it comes with poor traction, frequent failures, casing loss, or downtime.
What is casing credit?
Casing credit is residual value received when a tire casing can be retreaded, sold, or credited by a vendor. It reduces lifecycle tire cost.