Add Yahoo as a preferred source to see more of our stories on Google. Knowing your loan's interest rate matters, as does learning how that rate is calculated. Interest is either simple or compound. If ...

Simple interest is used when a company borrows money for a loan. Usually this amount will be on a monthly basis. The formula for simple interest is principal times the interest rate times the period.

Principal is the amount you borrowed, and interest is the amount you pay to the lender as a charge for borrowing. To calculate interest, multiply the principal amount by the interest rate, then ...

Savings accounts will earn interest on the amount of money deposited into the account. The formula to calculate simple interest in a savings account is the deposit amount times the annual interest ...