Owner-Operator Guide

How To Calculate Your Cost Per Mile

Here's the whole thing in one line: add up a full year of fixed costs, divide by the miles the truck ran that year, then add your variable cost per mile and the road costs nobody logs. Fixed per mile plus variable per mile plus road costs per mile is your cost per mile — what it costs you to put one mile under the truck, loaded or empty. Below is each piece, the costs almost nobody writes down, and the full arithmetic worked out.

Why this number is hard to keep in your head

Most of us can quote what a load pays per mile without thinking about it. It's printed right on the rate confirmation. The cost side is different — it's scattered across a truck payment, an insurance draft, a fuel card, a shop invoice, a plate renewal that hits once a year, and forty dollars in cash at a counter in Amarillo. There's no piece of paper anywhere that adds it up for you. That's the whole problem, and it's a bookkeeping problem before it's a math problem.

I drove for years before I ever sat down and did this properly. Once you've got the number, a rate stops being a rate and starts being a comparison — this many cents coming in against that many cents going out. It doesn't make a cheap load pay better. It just means you know which one it is before you say yes.

Step 1 — Fixed costs (they don't care if you move)

Fixed costs are the ones that come due on a calendar, not on an odometer. Whether you run 12,000 miles this month or sit in the yard for two weeks with a bad injector, the truck payment and the insurance draft show up anyway. Pull twelve months of them out of your books and total them for the year — including the annual ones that don't feel like monthly costs.

These are example figures to show the method — a payment, a premium, and a plate bill for a truck running long miles. Yours will be different, and that's the point. Use your own.

Now divide by the miles. At 100,000 miles a year: $47,048 ÷ 100,000 = $0.470 per mile in fixed cost, before a single gallon of fuel.

Step 2 — Variable costs (they run with the odometer)

Variable costs are the ones the road creates. They're already per-mile by nature, so you don't need to annualize them — though for tires and maintenance it's easier to total a year and divide, same as the fixed side, because they hit in lumps.

Fuel is the easy one and it's worth doing by hand: price per gallon divided by your real MPG. At $3.90 a gallon and 6.5 mpg, that's $0.60 a mile. Your real MPG is the one out of your own fuel records, not the one on the door sticker — and it moves with the season, the weight, and the hills.

Maintenance is the line people low-ball. It isn't just oil changes. It's the alternator on a Sunday, the dry-van door that got backed into, the DPF, the tow bill. Total what a full year actually cost — not what a good year costs — and divide by the miles.

Step 3 — The costs nobody logs

This is the group that quietly ruins the number. Showers. Reserved parking. Food away from home. Laundry. A pair of gloves, a marker light, a jug of oil, a bungee, a phone charger — all bought at a counter, all paid for and forgotten by the next exit. None of them produce a bill you can point to at the end of the month, so they never make it into anybody's math.

Put a real number on them. In this example: $150 a week across 50 working weeks = $7,500 a year, or $0.075 a mile. Seven and a half cents doesn't sound like anything until you multiply it by 100,000 miles.

One thing to keep straight: counting a cost for your cost-per-mile math is a completely separate question from whether that cost is deductible on your taxes. Per-diem rules, what counts as a business expense, what needs a receipt — that's IRS territory and your accountant's call, not something a calculator decides.

Step 4 — Every mile goes in the denominator, including deadhead

Here's where a lot of cost-per-mile math quietly goes wrong. The truck doesn't know whether there's freight on the trailer. An empty mile burns the same fuel, wears the same tires, and eats the same share of the truck payment as a loaded one. So every mile the truck turns belongs in the denominator — deadhead, bobtail, the run to the shop, the twelve miles of crawling around looking for a parking spot at nine at night.

Leave the empty miles out and the number comes back low, which makes every load look better on paper than it is. Say the truck turns 100,000 total but only 88,000 of those are loaded. Divide fixed costs by loaded miles only and you get $47,048 ÷ 88,000 = $0.535 a mile — six and a half cents higher than the all-miles figure. That gap doesn't go away just because it's off the page.

Either denominator can be made to work. The rule is don't mix them. If total miles are on the bottom of your cost, then total miles go on the bottom of your revenue too. Cost per total mile against revenue per total mile. Apples to apples, every time.

The whole thing, worked out

Now put a load against it. A broker offers $1,050 for 500 loaded miles — $2.10 a mile, which sounds fine. But it's 120 deadhead miles to get to the shipper. That's 620 miles the truck actually turns.

• Revenue per total mile: $1,050 ÷ 620 = $1.694
• Cost for 620 miles: 620 × $1.385 = $858.70
• Left over: $1,050 − $858.70 = $191.30, or about 31¢ a mile

Count only the 500 loaded miles and the cost comes out at $692.50, which makes it look like $357.50 left over. The 120 empty miles cost about $166 to run — a little over $100 of that in fuel and running costs — whether they show up in your math or not. That's the same load, described two different ways.

Why the number moves, and why you re-run it

Cost per mile isn't a number you calculate once and tape to the dash. It's a photograph of a month. Fuel swings forty cents. Insurance renews higher. You put on a set of drives. The truck gets paid off and a big chunk of fixed cost disappears overnight.

The one that surprises people is a slow month. Those fixed costs work out to about $3,920 a month in our example. Run 8,333 miles and that's 47¢ a mile. Run 6,000 miles — bad weather, a week in the shop, freight just isn't there — and the same $3,920 gets spread across fewer miles: 65¢ a mile. Eighteen cents higher, and nothing about the truck changed. The bills came due anyway.

That's why the cushion matters. The JPMorgan Chase Institute looked at small businesses back in 2016 and found the typical one was holding about 27 days of cash buffer — under a month of expenses with nothing coming in. A truck is a small business with an expensive calendar attached to it. Re-run this monthly, and again any time something big changes.

It all comes back to the books

Every number in this guide came from somewhere. Fixed costs come from twelve months of statements. Fuel cost per mile comes from fuel records and real MPG. Maintenance comes from shop invoices you kept. The road costs come from receipts most people throw away at the pump.

That's the actual work — not the division at the end. If the receipts are logged as they happen and the settlements are recorded line by line, cost per mile is something you look up in a few seconds. If they're in a shoebox, it's a Saturday you'll never get back, and the answer will be a guess.

That's the reason HaulProof exists — bookkeeping built for the truck instead of general-purpose bookkeeping software written for somebody with an office. Snap a receipt in the cab and it's filed. Drop in a settlement and it gets read line by line, with short-pays and deductions flagged for a second look. Cost per mile stops being a project and turns into a number that's already sitting there. If you want to see what's on a settlement before you upload one, here's how to read a broker settlement statement line by line.

Common questions

All dollar figures in this guide are examples used to show the method — they are not survey data and they are not your numbers. This is general education for owner-operators, leased-on drivers, and box-truck operators, not legal, tax, or financial advice. What is deductible, what a broker owes you, and what your settlement should say are governed by IRS rules and by your own contract and carrier agreement. Tools help you document and calculate; they don't decide any of that. Built by a driver, for drivers.