Cost Per Mile Calculator — fixed and variable driving costs

How it works

Driving costs split into two kinds. Fixed costs — insurance, registration, depreciation, a loan or lease payment — are owed whether you drive 5,000 miles or 25,000, so their share per mile shrinks as the odometer climbs. Variable costs — fuel, tires, maintenance — are incurred by the mile, so their per-mile rate stays put. Add the two and you get the true cost of a mile. The miles sweep makes the fixed-cost leverage visible: the same $4,000 of fixed costs is $0.80 a mile at 5,000 miles but $0.20 a mile at 20,000, pulling the total per-mile cost down toward the variable rate.

Worked example

For a benchmark, the IRS sets a 2026 business standard mileage rate of 72.5 cents per mile, derived from an annual study of the fixed and variable costs of operating an automobile — feed $7,250 of annual cost over 10,000 miles and this page returns exactly $0.725. Heavy trucks cost far more: ATRI put the 2023 marginal cost of operating a truck at $2.270 per mile, which $227,000 over 100,000 miles reproduces. Your own car sits between: $4,000 fixed over 12,000 miles is $0.33 per mile, plus $0.18 variable, for about $0.51 a mile — this calculator's arithmetic on your figures.

Frequently asked questions

How do I calculate cost per mile?

Divide your fixed annual costs by the miles you drive in a year, then add the variable cost per mile. $4,000 fixed over 12,000 miles is $0.33; plus $0.18 of fuel and upkeep, that's about $0.51 a mile. The more miles, the lower the fixed share and the lower the total per mile.

What counts as a fixed cost versus a variable cost?

Fixed costs don't change with mileage: insurance, registration, depreciation, and any loan or lease payment. Variable costs rise with miles: fuel, tires, routine maintenance, and repairs. Depreciation is partly mileage-driven in reality, but it's usually treated as fixed for a yearly estimate.

Why does cost per mile drop the more I drive?

Because the fixed costs are divided by miles — spread over more miles, each one carries a smaller slice. The variable rate stays the same, so the total per-mile cost falls toward it. It never reaches the variable rate, though: the fixed share shrinks but never hits zero.

How does this compare to the IRS mileage rate?

The IRS 2026 business rate of 72.5 cents per mile is a nationwide average from its annual cost study, meant for tax deductions and reimbursements. Your actual cost per mile can be higher or lower depending on your vehicle, insurance, and how much you drive. Use the IRS rate for taxes; use your own figures here to see your real cost.

Why is a truck's cost per mile so much higher?

Fuel, maintenance, tires, and driver-related costs are far larger for a heavy truck than a car — ATRI's 2023 figure was $2.270 per mile, over four times a typical car. Excluding fuel it was still $1.716. The structure is the same (fixed spread over miles plus variable); the magnitudes are much bigger.

Does this include depreciation and the cost of my time?

It includes depreciation if you enter it as a fixed cost — estimate the year's drop in the vehicle's value. It does not include the value of your time, tolls, or parking, which vary by trip. Add tolls and parking to variable costs if you want them in the per-mile figure.

How accurate is this, and what does it exclude?

The arithmetic is exact for the fixed costs, variable rate, and miles entered. Its accuracy depends on your inputs — depreciation and maintenance are estimates, and fuel cost per mile shifts with prices and driving. It excludes taxes, the mileage-vs-time tradeoff, and any resale value beyond the depreciation you enter.