The simple interest formula helps to find the interest amount earned on a loan, principal amount of the loan or investment, period of the loan investment and the rate of interest. The amount that is earned on a principal amount for a certain period of time at an interest rate is called as simple interest.

P [sum] = (SI x 100) / (R x T)

R [Rate/year] = (SI x 100) / (P x T)

T [Time] = (SI x 100) / (P x R)

S.I. = Simple Interest

P = Principal or Sum of amount

R = % Rate per annum

T = Time Span

Simple interest formula is product of principal, period of investment and rate of interest divide by 100. It can be used in places of mortgage, loan, savings account, investment etc.,