An interest rate is the price of using some entity’s money for a period of time, or the price of your money that you use to acquire goods and services. When you loan money to another entity, the price you charge for that money is the interest rate. When you use another entity’s money to acquire something, as in the form of obtaining credit for a loan or to use a credit card, the price charged to you for using that money over some period of time is commonly referred to as the interest rate.