How to Calculate Your Trucking Cost Per Mile

Your cost per mile (CPM) is the number every other decision hangs on. Whether a load pays, how much deadhead you can afford, and whether that lease deal is worth it all come back to it. If you only know one number about your business, make it this one.

The formula

Cost per mile = total monthly costs ÷ total monthly miles.

Total monthly miles means every mile you ran, loaded and empty. Deadhead burns the same fuel and wears the same tires as loaded miles, so it counts.

Split it into fixed and variable

One number is useful. Two numbers are more useful.

• Fixed costs are the bills that show up even if the truck sits all month. That means the truck and trailer payment, insurance, plates and IRP, permits, IFTA and UCR, your share of the annual 2290, the ELD subscription, your phone, and parking.
• Variable costs move with the miles. That means fuel, maintenance and repairs, tires, tolls and scales, and driver pay if you pay yourself or a driver by the mile.

Here's why the split matters. Fixed cost per mile drops when you run more miles, because the same payment gets spread over more of them. Variable cost per mile stays about the same. If your fixed CPM is high, the fix is usually more miles or a cheaper truck. If your variable CPM is high, look at fuel, speed, and maintenance.

Worked example

Say you ran 10,000 miles last month. Your fixed costs were:

• Truck payment: $2,200
• Insurance: $1,100
• Plates / IRP, monthly share: $200
• Permits, IFTA, UCR, 2290, monthly share: $150
• ELD: $45, phone: $80, parking: $125

That's $3,900 fixed. Divided by 10,000 miles, it comes to $0.390 per mile.

Your variable costs were:

• Fuel: $6,000
• Maintenance: $1,500
• Tires: $400
• Tolls: $150
• Driver pay (what you pay yourself): $5,000

That's $13,050 variable. Divided by 10,000 miles, it comes to $1.305 per mile.

Your all-in cost per mile is $0.390 + $1.305 = $1.695. A load has to pay at least that for every mile you run, empty ones included, just to break even. That also covers the wage you set for yourself.

Now watch the fixed side move. If you only ran 8,000 miles the next month, fixed cost per mile jumps to $3,900 ÷ 8,000 = $0.4875. Your all-in CPM rises to about $1.79, even though nothing about the truck changed.

Getting the numbers right

• Use more than one month. Repairs are lumpy. A $4,000 turbo in one month will wreck that month's number. Average three to six months, or use a maintenance reserve per mile instead of what you actually spent.
• Spread annual bills. Divide yearly costs like plates, the 2290, UCR, and permits by 12.
• Pay yourself. If you leave out your own pay, your CPM looks great and your bank account doesn't. Put in what you need to take home, as a monthly number or a per-mile rate.
• Count every mile. Use the odometer or ELD total, not just the loaded miles on your rate cons.

What to do with it

Once you have your CPM:

• Plug it into the load profit calculator to see what a load really pays after deadhead.
• Use the break-even rate calculator to turn it into the lowest rate per loaded mile you can take.
• Check how much of it is maintenance with the maintenance cost per mile calculator.

Redo it every quarter, or any time something big changes, like a new truck, new insurance, or a fuel price swing. A CPM from last year is a guess, not a number.