Cost per mile (CPM) is a period calculation, not a per-load one. Pick a timeframe with enough data to be representative — a quarter is common — and total two buckets. Fixed costs are the ones you pay whether the truck moves or not: the truck and trailer payment, physical damage and liability insurance, plates and permits, ELD subscription, accounting and factoring fees, and parking. Variable costs scale with miles: fuel, maintenance and repairs, tires, oil, tolls, and def.
Divide the combined total by the miles you actually drove in the period, including deadhead. Dividing by loaded miles only makes your CPM look better than it is and leads you to accept loads that do not cover the truck.
Most owner-operators land somewhere in a broad range once everything is counted, and the number moves with fuel price and how many miles the truck runs — the same fixed costs spread over fewer miles push CPM up. Recalculate when fuel moves sharply, when you add a fixed cost, or at least every quarter.
CPM is the floor for pricing. A load has to beat your all-in CPM on total miles, including the deadhead to reach it, before it adds anything to the bottom line.
| Bucket | Examples | Behavior |
|---|---|---|
| Fixed | Truck/trailer payment, insurance, permits, ELD, parking | Same each month; CPM rises when miles drop |
| Variable | Fuel, maintenance, tires, tolls, DEF | Scales with miles driven, including deadhead |
| Owner pay | A wage for your own driving and admin time | Left out of many CPM calculations, which hides the real number |
Terms in this answer: Deadhead, Linehaul
In Trailflow: accounting and settlements.