How to Calculate the Monthly Finance Charges on an Auto Loan
- 1). Divide the annual interest rate by 100 -- to convert the rate from a percent to a decimal. For example, if you have 11.28 percent rate, divide 11.28 by 12 to get 0.1128.
- 2). Divide the Step 1 result by 12, to find the monthly interest rate. In this example, divide 0.1128 by 12 to get 0.0094.
- 3). Multiply the Step 2 result by the amount you owe on your auto loan, to find the finance charges. You can find your current loan balance on the previous loan statement. Finishing the example, if you owe $8,930, multiply 0.0094 by $8,930 to get $83.94, as your monthly finance charge.