Example 3: Car Finance oExcel can help you calculate your mortgage or simple loan payments for given interest rate by using PMT formula. You don't have to know the background math! However, you must be sure that you have the same units for all parameters (if it's a monthly payment, interest rate and # of periods must be in months; if it's weekly or yearly, you must adjust your parameters accordingly). Assume you are purchasing a car for $18.5K, you present $2K as your down payment and your current vehicle has been praised at $3.5K trade-in value. You finance the remaining amount at the annual interest rate of 8% over 4 years. oYou will make monthly payments