Calculating cost per mile requires adding up every expense tied to running your truck and dividing by the miles you drive. The formula is simple. The challenge is capturing all the costs, not just the obvious ones.

Start with fixed costs. These don’t change based on miles driven but they’re real expenses that need to be spread across your total miles. Include truck payments or lease costs, insurance premiums, permits and licensing fees, and base plate registration. If you own your truck outright, include depreciation because you’ll eventually need to replace it. Trucking companies that skip depreciation end up shocked when it’s time to buy a new truck and the money isn’t there.

Variable costs change with how much you drive. Fuel is the biggest one, usually 25% to 40% of your total cost per mile. Maintenance and repairs add up faster than most owner-operators expect. Tires wear out based on miles. Oil changes, brake jobs, and unexpected breakdowns all factor in.

Then add the costs most truckers forget. Deadhead miles cost money even though you’re not hauling a load. Your phone, ELD subscription, and factoring fees are business costs. If you stay out on the road, meals and lodging add up. And the biggest one people miss is owner compensation. If you’re not including what you need to pay yourself, you’re subsidizing every load you haul.

Track actual expenses, not estimates. Keep receipts and log everything. A QuickBooks bookkeeper in Santa Fe who understands trucking can help you categorize expenses properly so you’re working with real numbers instead of guesses.

Once you have total monthly expenses and total monthly miles, the math is straightforward. If you spent $12,000 and drove 8,000 miles, your cost per mile is $1.50. Any load paying less than $1.50 per mile is losing you money before you even factor in profit margin.

Update your calculation regularly. Fuel prices change. Maintenance costs increase as trucks age. Insurance premiums fluctuate. A cost per mile you calculated a year ago probably isn’t accurate anymore.

Knowing your real cost per mile lets you make smart decisions about which loads to take. When a broker offers $1.80 per mile, you know whether that’s a profitable run or a loss waiting to happen. Without accurate numbers, you’re just guessing.