The formula (simple) and the discipline (not)
Cost per mile = total monthly costs ÷ total monthly miles. The formula is arithmetic; the discipline is in capturing every cost and using all miles, including deadhead. Miss either and the number flatters you, which is worse than having no number at all.
Fixed costs: what you pay whether the wheels turn or not
These continue through breakdowns, home time, and slow freight, which is exactly why they matter most. Monthly fixed costs for a typical single-truck operation:
- Truck payment: $1,800–$3,500 for a financed late-model truck (a paid-off truck still 'costs', see the depreciation note below)
- Trailer payment or rent: $400–$900 if you pull your own
- Insurance: $900–$1,800+ for liability, cargo, and physical damage, new authorities pay the top of that range and beyond
- Plates, permits, and heavy vehicle use tax: IRP registration, 2290, state permits, commonly $250–$400 monthly when annualized
- ELD, load boards, dispatch software, parking: $100–$300
- Health insurance and your own pay floor: the fixed cost owner-operators most often omit, the business must cover the driver's life, or the number is fiction
Variable costs: what each mile consumes
- Fuel, the monster: at roughly $3.50–$4.00/gallon and 6.5 mpg, you're burning $0.55–$0.62 every mile. Track actual, not vibes; your fuel card statements have the real number
- Maintenance and repairs: budget $0.15–$0.20/mile even when nothing is breaking, because the $4,000 brake job and the eventual $15,000+ in-frame are mileage-driven certainties, not surprises. This line is a reserve, not an expense you notice
- Tires: a full set every 100–150K miles works out to $0.03–$0.05/mile
- Tolls, scales, washes: route-dependent, pull it from your actual statements
A worked example with honest numbers
Single truck, 9,500 total miles a month (8,500 loaded + 1,000 deadhead). Fixed: truck $2,400, trailer $600, insurance $1,300, permits/2290 $300, tech $200: $4,800/month. Variable: fuel $5,500 (actual card spend), maintenance reserve $1,600, tires $400, tolls $350: $7,850. Total: $12,650 ÷ 9,500 miles = $1.33/mile before the driver earns a dollar.
Add a livable owner wage, say $6,000/month, and the true all-in number is $18,650 ÷ 9,500 = $1.96/mile. That's the rate floor. A $2.05/mile load isn't 'decent freight'; it's nine cents of margin. A $1.80 load is a donation to the broker. And note what deadhead did: computing on loaded miles only would have understated cost by 11%, the flattering lie that sinks people.
The four mistakes that make CPM lie
- Loaded-miles-only math, all miles consume fuel and truck; divide by all of them
- No maintenance reserve, the number looks great for eight months, then one repair erases a quarter's 'profit' that never existed
- Ignoring depreciation on a paid-off truck, the truck is still being consumed; $0.10–$0.15/mile into a replacement fund is what keeps a paid-off truck from becoming a debt trap when it dies
- Computing it once, fuel moved 30% in a year before; a January CPM quoted against September fuel is fantasy. Recompute monthly from actuals
From spreadsheet to system
A spreadsheet works at one truck if you maintain it. What breaks it: settlements arriving netted (gross revenue and deductions need splitting, factoring fees are a cost, not a revenue reduction), fuel across multiple cards and states (which you need per-state anyway for IFTA: IFTA for Owner-Operators: Quarterly Filing Without the Panic ), and any second truck, at which point per-truck P&Ls become the question a spreadsheet can't answer. That's the point of trucking-specific bookkeeping: every settlement reconciled, every cost captured monthly, and CPM as a standing report instead of a winter project. Trucking
Frequently asked questions
What's a 'good' cost per mile in 2026?
Typical all-in operating costs (before owner pay) run $1.60–$2.00/mile for single-truck operations, but the spread is the point, your insurance, your truck note, and your lane's deadhead make your number. The market's average CPM never paid anyone's bills; yours decides everything.
How do I lower mine?
In order of real impact: fuel discipline (network discounts, speed, idle time), deadhead reduction (better booking beats better mpg), insurance shopping at renewal, and maintenance done scheduled rather than roadside, an emergency repair costs multiples of the same job planned.
Does CPM change how I book loads?
It should change everything: your floor rate, which lanes you accept, whether that backhaul at $1.70 is 'better than deadhead' (only if it clears variable cost, about $0.85 in the example above, and it usually does; that's the one place cheap freight is rational).