Final answer:
Compound interest is an interest rate calculation on the principal plus the accumulated interest. The formula for finding compound interest is Compound interest = Future Value - Present Value.
Step-by-step explanation:
Compound interest is an interest rate calculation on the principal plus the accumulated interest. To find the compound interest, you can use the formula Compound interest = Future Value - Present Value. For example, if you start with a principal amount of $100 and earn an interest rate of 5% for three years, the future value would be $115, and the compound interest would be $15.