Interest rate

An interest rate (hereinafter, the Rate) is a payment calculated as a percentage of the original amount saved or borrowed, and paid by the borrower to the saver. Frequently, the Rate refers to the annual percentage rate (APR).

Definitions

According to Principles of Economics by Timothy Taylor (3rd edition),

Interest rate. A payment calculated as a percentage of the original amount saved or borrowed, and paid by the borrower to the saver.

According to Macroeconomics by Mankiw (7th edition),

Interest rate. The market price at which resources are transferred between the present and the future; the return to saving and the cost of borrowing.