27 Nov 2012 I know how to solve for a loan discount at a certain interest rate (say Can you state the equation you are working with to calculate the loan Interest rate is the percentage of a loan paid by borrowers to lenders. For most loans, interest is paid in addition to principal repayment. Loan interest is usually expressed in APR, or annual percentage rate, which include both interest and fees. The rate usually published by banks for saving accounts, money market accounts, and CDs is the annual percentage yield, or APY. It is important to understand the difference between APR and APY. Interest rate is the amount charged by lenders to borrowers for the use of money, expressed as a percentage of the principal, or original amount borrowed; it can also be described alternatively as the cost to borrow money. For instance, an 8% interest rate for borrowing $100 a year will obligate a person to pay $108