What your car costs you each month

Enter your own numbers and the calculator adds them up. It shows what the car costs each month and what each mile costs.

Where to find your numbers

• Miles a year. Take the odometer reading now and subtract the reading from a repair order about a year old. Every completed repair order lists the odometer reading.
• Miles per gallon. Your own fuel log gives the truest figure. Divide the miles driven between fill-ups by the gallons it took to refill.
• Fuel a gallon. Use what you pay at your usual station. The U.S. Energy Information Administration publishes the national average price for regular gas each week.
• Insurance a year. Use the premium on your auto policy's declarations page. If the policy runs six months, double it.
• Maintenance a year. Add up the last year's repair orders. Each one lists the repairs, the parts and their cost, and the labor.
• Registration a year. Use the amount on your last renewal notice.
• Depreciation a year. This is how much the car's value drops in a year. Compare what it's worth now with what it was worth a year ago, using the same pricing guide both times.
• Loan payment a month. Use the payment on your loan statement, or zero if the car is paid off.

What the figures mean

A month spreads each yearly cost evenly across twelve months, then adds the loan payment. A mile is the year's total divided by the miles you drive. Fuel has its own line because it rises and falls with your miles and the price at the pump.

Depreciation doesn't come out of your account each month, but it's still a cost. It's the value the car loses while you own it, and you feel it when you sell or trade it in.

Costs it leaves out

Parking, tolls, car washes and tickets aren't in the calculator. If you pay them regularly, add a yearly figure to maintenance. One big repair can make a year's maintenance look high, so an average of two or three years of repair orders gives a steadier number.

Keeping it current

The numbers that change most are the price of fuel and the miles you drive. Logging each fill-up keeps both up to date, and a new insurance or registration bill is the time to update those lines. How to track your car's fuel use and cost per mile shows how.