Car depreciation per mile: the cost nobody logs

Why depreciation is the largest single cost of owning a car

Drivers obsess over a five-cent difference in gas prices or an extra two miles per gallon. Yet on almost any late-model vehicle, fuel is an insignificant line item compared to depreciation.

When you purchase a new vehicle for $42,000 (the median price of a new car in North America), it loses approximately 20% of its value in the first year alone—over $8,000 in lost equity. If you drive 12,000 miles that year, depreciation cost you $0.68 per mile before buying a single gallon of gas, paying an insurance premium, or rotating a tire.

The 5-year depreciation curve

Vehicle value loss does not occur in a straight line. It follows a steep logarithmic decay curve that is steepest during the first 36 months:

By year five, the average vehicle has lost nearly 55% to 60% of its original purchase price. Beyond year seven, the depreciation curve flattens into a gentle plateau where utility and mechanical condition govern resale value rather than odometer increments.

How to calculate your personal depreciation per mile

To find your car's true per-mile depreciation rate, you need three numbers: what the car was worth at the beginning of a window, what it is worth on private sale platforms today, and the miles driven between those dates:

You can calculate your complete vehicle running cost—including fuel, insurance, maintenance, and depreciation—instantly in our in-browser cost per mile calculator.

Mileage penalties vs calendar age: which costs more?

A common misconception among commuters is that adding miles to the odometer is what destroys a car's value. In reality, calendar age accounts for roughly 65% to 75% of total depreciation, while excess mileage accounts for the remaining 25% to 35%.

Automotive valuation benchmarks (Kelley Blue Book, Edmunds) apply a marginal mileage penalty of approximately $0.08 to $0.14 per mile above standard usage (12,000 miles/yr) on late-model vehicles. A three-year-old car with 25,000 miles is worth only about $1,800 to $2,500 more than an identical three-year-old car with 45,000 miles.

Parked cars still lose value every month they sit unused because technology ages, styling refreshes occur, and factory warranties tick down on the calendar.

The financial floor: why keeping an older car is the ultimate cheat code

Once a reliable Japanese or domestic vehicle (such as a Honda Accord, Toyota RAV4, or Ford F-150) reaches 10 to 12 years of age, depreciation effectively drops to near zero. A running, clean commuter car with working air conditioning and valid safety inspection commands a 'utility floor' of $4,000 to $6,000 regardless of whether the odometer reads 130,000 or 160,000 miles.

On an older vehicle, your depreciation per mile is practically pennies ($0.02 to $0.04/mile). Even if you spend $1,800 a year on repairs and maintenance—calculated in our car maintenance cost calculator—your total cost of ownership remains thousands of dollars cheaper per year than driving a new lease or financing a late-model car.

How the IRS treats depreciation in mileage rates

If you use your vehicle for business, rideshare, or self-employment, the IRS standard mileage rate (67 cents per mile) already includes a built-in allowance for depreciation (typically around 28 to 30 cents per mile).

This creates a massive tax arbitrage for drivers of older vehicles: you deduct the full 67 cents per mile on your tax return, but your real-world car is only depreciating at 4 cents per mile. Review the record-keeping requirements in our guide on how to track car expenses for taxes.

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