Calculate simple interest and total amount
Simple interest is charged only on the original amount, not on interest already earned. This calculator finds the interest and the total amount from the principal, annual rate and time period. It is useful for school maths, short-term loans and quick comparisons.
Simple interest = P × R × T ÷ 100, where P is the principal, R the yearly rate in percent and T the time in years.
Simple interest is calculated on the principal only. Compound interest is also calculated on the interest that has already been added.
Simple interest is calculated only on the original principal, and it does not earn interest on itself. The formula is SI = (P × R × T) ÷ 100, where P is the principal, R is the annual rate in percent and T is the time in years. The total amount you receive or repay is Principal + Simple Interest.
Simple interest is common in short-term personal lending, some fixed deposits that pay out interest regularly, school and textbook problems, and informal loans between people.
Example 1: ₹50,000 at 8% per year for 3 years. SI = (50,000 × 8 × 3) ÷ 100 = ₹12,000.00. Total amount = ₹62,000.00.
Example 2: ₹1,20,000 at 6.5% for 2.5 years (30 months). SI = (1,20,000 × 6.5 × 2.5) ÷ 100 = ₹19,500.00. Total amount = ₹1,39,500.00.
Simple interest is always charged on the original principal. Compound interest is charged on the principal plus the interest already added, so it grows faster over time.
Rearrange the formula. Rate = (SI × 100) ÷ (P × T) and Time = (SI × 100) ÷ (P × R).
Yes, but convert the period into years first. Divide the number of months by 12, or the number of days by 365.
Most bank loans use reducing-balance interest, while some short-term loans and certain deposits use simple interest. Always check how your lender calculates it.