The price on the window is the smallest honest number a car will ever show you. The real cost is everything that follows: the value it quietly loses, the gas it drinks, the insurance, the maintenance, the registration — added up across all the years you own it. This tool puts that full number in front of you, then breaks it down per year and per mile.
How it works
It sums five costs over the years you keep the car:
- Depreciation — the purchase price minus what you can sell it for later. This is usually the biggest cost, and the one drivers forget, because you never write a check for it.
- Gas — miles you drive ÷ your fuel economy (MPG) × the price of a gallon, each year.
- Insurance, maintenance and tires, registration and fees — your yearly amounts, multiplied by the years.
Add them up and you get the total cost of ownership. Divide by years for the cost per year; divide by total miles for the cost per mile.
An example
Take the values already filled in: a $30,000 car you keep 5 years and sell for $15,000, driving 12,000 miles a year at 28 MPG, with gas at $3.50 a gallon, $1,500 insurance, $800 maintenance, and $150 registration a year. The total comes to about $34,750 — more than the car cost new. That’s roughly $6,950 a year, or about $0.58 a mile, of which only $0.13 is gas. And the single largest piece, $15,000, is depreciation — money you lose without ever seeing a bill. For comparison, the IRS lets businesses deduct 70 cents a mile in 2025, which folds in financing and is meant to cover a typical car’s all-in cost; your own number depends entirely on the inputs above.
The part that matters
The point isn’t that cars are bad — for many people they’re essential. The point is to see the whole cost, so you can compare honestly: a cheaper car you keep longer, a more efficient one, or skipping a second car altogether. Three honest notes:
- Depreciation is a guess until you sell. Resale value depends on the model, mileage, and the used-car market years from now. Use a conservative estimate, and remember that some cars hold value far better than others — which can matter more than the sticker price.
- It leaves out financing. If you take a loan, the interest is a real cost on top of this. Add it with the loan and APR calculator. AAA’s full study does include finance charges, which is part of why their headline number runs higher.
- The fewer miles you drive, the more each one costs. Fixed costs — depreciation, insurance, registration — don’t shrink when you drive less, so they spread over fewer miles. A barely-driven car can cost more per mile than a heavily-used one.
Change the numbers above to match the car you’re weighing — the one you own, or the one you’re about to buy — and watch the real cost come into view.