How to Calculate Your Trucking Cost Per Mile

If you don't know your cost per mile, you can't tell a good load from a bad one. You might be grossing $2.10 a mile and think things are going well, only to find out your true cost is $1.95 and you've been working 60-hour weeks for pennies. Cost per mile (CPM) is the floor below which you cannot haul and make money. Every rate negotiation, every load decision, starts here.

Fixed costs vs. variable costs

Split your costs into two buckets. Fixed costs hit you every month whether you run 8,000 miles or 14,000. Variable costs scale with the miles you turn.

Fixed costs (monthly)

• Truck payment or lease
• Primary liability and cargo insurance
• Bobtail and non-trucking liability (if leased on)
• IRP apportioned plates, prorated monthly
• BOC-3 process agent fee
• UCR registration, prorated monthly
• Trailer payment or rental
• Load board and dispatch subscriptions
• ELD and phone

Variable costs (per mile or per month, scaled to miles)

• Diesel fuel (largest single variable cost for most carriers)
• Reefer fuel if you pull temperature-controlled freight
• Tires, prorated over expected life (100,000 to 150,000 miles per drive set)
• Preventive maintenance: oil, filters, DEF, annual DOT inspection
• Unplanned repairs: budget a monthly reserve, usually $500 to $1,500 for trucks over five years old
• Tolls, averaged by route
• Lumpers if you end up covering them

The formula

Total CPM = (Monthly fixed costs + Monthly variable costs) divided by total miles driven that month. Total miles means all miles, loaded and empty. Your deadhead still burns fuel and wears your truck.

A worked example

Say you ran 10,000 miles in a month, 7,500 of them loaded. Diesel averaged $3.85 and your truck gets about 6.5 miles per gallon.

• Truck payment: $1,800
• Insurance (primary + bobtail): $1,100
• IRP + UCR + BOC-3 prorated: $180
• ELD + phone + load board: $150
• Fixed total: $3,230
• Fuel: 10,000 miles / 6.5 mpg x $3.85 = $5,923
• Tires reserve: $1,200
• Maintenance + repairs: $800
• Tolls: $120
• Variable total: $8,043
• Grand total: $11,273
• CPM: $11,273 / 10,000 miles = $1.13 per mile all-in

Now here is the part people miss. You only got paid for the 7,500 loaded miles. So your effective cost against revenue miles is $11,273 / 7,500 = $1.50 per loaded mile. A load at $1.80 per loaded mile gives you $0.30 to pay yourself, cover taxes, and save something. A load at $1.40 per loaded mile is losing money.

The two mistakes that sink owner-operators

First mistake: counting only fuel. Fuel is real, painful, and swipes your card every 600 miles. But your insurance alone might be over $1,000 a month. Leave that out and your CPM math is fiction.

Second mistake: forgetting deadhead in the denominator. A load paying $2.50 per loaded mile sounds great until you add 350 miles of empty running to get to the shipper. Spread your costs over 1,350 total miles and recalculate. The picture changes.

How often to update your CPM

Monthly is practical. Diesel prices move. Your repair costs are lumpy. If you take a week off or run light, fixed costs get spread over fewer miles and your CPM climbs. Run the numbers monthly and your floor rate stays accurate.

What a workable margin looks like

Most owner-operators with a healthy operation net 15 to 35 cents per loaded mile above CPM before owner compensation. If your CPM is $1.55 and you're consistently hauling at $1.60, you're not running a business, you're running a very expensive hobby. The difference between surviving and building something in this industry almost always comes down to knowing this number precisely and refusing to haul below it.