How to Calculate Your Trucking Cost Per Mile (and Why It Decides Every Load)
Cost per mile (CPM) is the single most important number in your trucking business. It is the line in the sand that tells you whether a load makes money or quietly costs you money. Brokers know their numbers cold — if you don't know yours, you are negotiating blind.
This guide walks through exactly how to calculate it.
Why cost per mile matters more than rate per mile
A load paying $2.10 per mile sounds better than one paying $1.95. But if your true cost is $1.85 per mile, the difference between those two loads is the difference between a $0.25 and a $0.10 margin — a load that earns 2.5x more profit. And if your cost is actually $2.00 because you forgot to account for an empty backhaul, that "good" load is losing money.
You cannot make that judgment without a CPM you trust.
Step 1: Add up your fixed costs
Fixed costs are the bills that arrive whether the truck rolls or sits. Per month, total up:
- Truck and trailer payments
- Insurance (liability, cargo, physical damage)
- Permits, licensing, IFTA, and IRP
- ELD subscription and other recurring software
- Accounting, dispatch, or factoring fees
- Parking and any office overhead
Add it all up and divide by the miles you realistically run in a month. If your fixed costs are $6,500 and you run 10,000 miles, that's $0.65 per mile before the truck even moves.
Step 2: Add up your variable costs
Variable costs scale with the miles you drive:
- Fuel — usually your single largest variable cost
- Tires
- Maintenance and repairs (set aside a per-mile reserve even in good months)
- Tolls
- Def, oil, and consumables
Track these per mile. Fuel alone is often $0.50–$0.70 per mile depending on your truck and lane.
Step 3: Don't forget the driver
If you pay yourself or a company driver, that pay is a real cost. Whether you express it as a per-mile rate, a percentage, or a salary divided by miles, it belongs in the calculation. Leaving driver pay out is the most common way owner-operators fool themselves into thinking a lane is profitable.
Step 4: Account for deadhead
Your costs accrue on empty miles too. If you run 10% deadhead, your effective cost per loaded mile is higher than your raw CPM. Divide total costs by loaded miles, not total miles, to get the number that actually matters when you quote a rate.
Putting it together
A simplified example for a single-truck operation:
| Category | Cost per mile |
|---|---|
| Fixed costs | $0.65 |
| Fuel | $0.60 |
| Maintenance + tires | $0.20 |
| Driver pay | $0.55 |
| Total | $2.00 |
Now you know: any load under $2.00 per loaded mile loses money. A load at $2.50 nets $0.50 per mile. That is your decision rule.
Keep the number current
Your CPM is not a one-time exercise. Fuel moves, insurance renews, a major repair changes the maintenance line. Recalculate quarterly — or let your software do it continuously.
This is exactly where a TMS earns its keep. In MantleTMS, every expense you log can be attributed to a load, a driver, or a power unit, and the trip-profitability report turns that ledger into a per-load margin automatically — so your cost per mile stays live instead of living in a spreadsheet you update twice a year.
Start free and put a real number behind every load you book.