When analyzing a loan or an investment, it can be difficult to get a clear picture of the loan's true cost or the investment's true yield. There are several different terms used to describe the interest rate on a loan, including annual percentage yield, annual percentage rate, effective rate, nominal rate, and more. In all of these, the effective interest rate is the most useful, it shows a relatively complete picture of the true cost of borrowing. To calculate the effective interest rate on a loan, you will need to understand the loan's specified terms & conditions and perform a simple calculation. What is an effective interest rate? The effective interest rate is the actual return on a savings account or any other interest-paying investment when the effects of compounding over time are taken into account. It also reveals the actual percentage rate owed as an interest on a loan, a credit card, or any other debt. The effective interest rate is also called the effectiv...