How to calculate your cost per mile (with the exact formula)

Cost per mile is the number a broker is quietly betting you don't know. If you do, every rate conversation changes: you can say "that's under my cost" and mean it, and you stop taking loads that only look good because the rate per mile is high. Here's the formula, every cost that belongs in it, and a full worked example you can check against your own truck.

The formula

Three things in that line trip people up.

1. Same period, every number. If the costs are monthly, the miles are monthly. Annual insurance gets divided by 12 before it goes in. A quarterly 2290 payment gets divided by 3.
2. Total miles, not loaded miles. Deadhead miles burn fuel, wear tires and eat hours exactly like loaded miles do. Dividing by loaded miles only makes your cost look higher than it is, which sounds safe but leads to wrong decisions on short, mostly-loaded lanes. You'll use loaded miles for one thing only: your breakeven rate (below).
3. Driver pay counts even when the driver is you. If you don't pay yourself a wage in the model, your "profit" is actually your paycheck, and you can't tell the two apart when a rate is marginal.

What goes in: fixed costs

Fixed costs are the bills you owe whether the truck moves or sits. Monthly amounts:

• Truck payment and trailer payment (or lease)
• Insurance: liability, cargo, physical damage, bobtail or non-trucking liability
• Plates and IRP registration (annual ÷ 12)
• Permits: UCR, Form 2290 heavy vehicle use tax (annual ÷ 12), state permits
• ELD subscription, load-board subscription, phone and internet
• Parking, accounting or bookkeeping software, a flat dispatch fee if you pay one

What goes in: variable costs

Variable costs scale with miles. Some are easy (fuel); some are reserves you set aside so the bill doesn't surprise you later:

• Fuel = total miles ÷ MPG × price per gallon. Use the MPG your ELD or fuel card actually reports, not the brochure number.
• DEF — a few percent of fuel gallons; a monthly dollar figure is fine.
• Tire reserve per mile. A set of drives and steers divided by the miles you'll get from them.
• Maintenance and repair reserve per mile. Older truck, higher number.
• Tolls, scales, lumpers you aren't reimbursed for.
• Factoring fee (a percent of invoices), dispatch service fee (a percent of linehaul), quick-pay fees.
• Weight-distance taxes if you run New York, Kentucky, New Mexico or Oregon.

What goes in: driver pay

Per-mile pay on all miles or loaded miles, a percent of linehaul, or a flat monthly draw. Pick the one you really use and put it in as a separate line so you can see driver cost per mile on its own.

Worked example: one dry van, 9,500 miles a month

These are the example numbers that ship inside the HaulMath Cost Per Mile Calculator: 8,700 loaded miles and 800 empty miles (9,500 total), 6.5 MPG, fuel at $3.85.

Split it and the story gets useful: fixed cost is $4,935 ÷ 9,500 = $0.52/mi, variable (everything that scales with miles, driver excluded) is $8,246.27 ÷ 9,500 = $0.87/mi, and the driver is $0.60/mi. Fuel alone is $0.59 of that, which is why a 50-cent swing at the pump moves your whole cost structure.

Breakeven rate per loaded mile

Brokers quote per loaded mile, so you need your cost expressed the same way. This is the one place loaded miles go in the denominator:

Any rate under $2.17 per loaded mile loses money at this month's miles and this month's deadhead. Offered $2.35? That's $0.18 above breakeven, and at 8,700 loaded miles it's about $1,564 of profit for the month. Offered $2.10? You're paying to haul it.

Note that deadhead is baked in here: 800 empty miles out of 9,500 is 8.4% deadhead. If next month's deadhead doubles, the breakeven climbs even though not a single bill changed.

Why cost per mile drops when you run more miles

Fixed costs don't care how far you drove. Spread $4,935 over more miles and the per-mile share shrinks, while variable and driver cost per mile stay put:

That table assumes the same deadhead percentage at every mileage. It is the honest version of "run harder and the numbers work" — true, but only by about 30 cents a mile between a slow month and a strong one. It is not a reason to take a bad load; it's a reason to keep the truck moving on good ones.

The two mistakes that make most numbers wrong

Leaving out the reserves. A truck with no tire or maintenance line in the model looks about 16 cents a mile cheaper than it is, right up until the month it needs steers and an EGR cooler. Put the reserve in, move the money to a separate account, and the repair becomes a withdrawal instead of a crisis.

Using last year's fuel and this year's rates. Fuel is the biggest variable cost and the one that moves weekly. Update price and MPG monthly; everything downstream, including breakeven, shifts with it.

Do it once, then keep it current

You don't need to redo this from scratch every month. Build it once with every line labeled, then update the handful that change: fuel price, MPG, miles, deadhead and anything you renegotiated. Ten minutes a month keeps the number you quote honest.

More guides

• IFTA explained for new owner-operators: how the quarterly return math works
• What a load actually pays: rate per mile vs. profit per day

Calculation guidance, not tax, legal or compliance advice. Verify rates and deadlines with your tax professional and the agencies named above.