P principal amount invested r rate of interest per interest period eg 10 per year t number of interest periods eg 2 years Example. This can be determined by multiplying the 1000 original balance times 1 10 3 or times 130. This may seem high but remember that in the context of a loan interest is really just a fee for borrowing the money.
In simple words Simple interest represents a fee that you pay on a loan or income that you earn on deposits.
When you borrow money you pay interest to the lender. The Formula for simple interest helps you find the interest amount if the principal amount rate of interest and time periods are given. Where SI simple interest. SI P R T 100.