# Interest Rates

In the world of banking and finance, interest is money that is paid by a borrower to a lender in exchange for the use of the credit. Money held in an account, such as a bank savings or checking account, may earn interest also because the bank has use of the money while it is held in the account and the interest constitutes payment to the account holder for the temporary use of the money.

Typically, interest is computed as a percentage of the amount borrowed, which is known as the principal. Interest may be computed on a yearly basis, which is known as simple interest. For example, if a borrower borrows \$1,000 at a simple interest rate of 12 percent, with the loan due to be repaid in one year, the total interest owed on the loan is \$120. Alternatively, interest may be compounded. With compounded interest, the calculation of interest occurs periodically and unpaid interest is added to the premium. For example, assuming a loan of \$1,000 with a 12 percent interest rate compounded monthly, the interest that accrues during the first month of the loan is \$120. That amount is added to the principal, making the total amount \$1,120. The interest accruing during the second month of the loan—12 percent of \$1,120—is \$134.40. With compounded interest, the interest rate stays the same but the amount of interest may increase periodically.