Simple Interest

Simple Interest is a method of calculating interest where the interest amount is computed only on the original principal throughout the entire loan or investment period, without adding any interest on accumulated interest.

It is straightforward and predictable, making it easy to calculate the total interest earned or payable over a given period. What is Simple Interest? The formula is SI = P × R × T / 100, where P is the principal, R is the annual interest rate, and T is the time in years. For a ₹2 lakh fixed deposit at 6.5% per annum for 3 years, the simple interest earned is ₹2,00,000 × 6.5 × 3 / 100 = ₹39,000. The maturity value is ₹2,39,000. Simple interest is typically used for short-term loans and investments in India, such as short-term fixed deposits (less than 1 year), some personal loans, and certain bond instruments. Most fixed deposits above 1 year use compound interest (compounded quarterly), which is more beneficial for the investor. The key difference between simple and compound interest becomes apparent over longer periods. For a 1-year deposit, the difference is negligible. But for a 5-year deposit of ₹5 lakhs at 7%, simple interest yields ₹1.75 lakhs total, while compound interest (quarterly) yields approximately ₹2.01 lakhs — a ₹26,000 difference. Simple interest is also used in certain government savings schemes in India. For example, the interest on the Senior Citizens Savings Scheme (SCSS) is calculated on a simple interest basis and paid quarterly. The Pradhan Mantri Vaya Vandana Yojana (PMVVY) also uses a simple interest payout structure. However, most government small savings schemes now use compound interest methodologies. For investors, simple interest instruments are preferable when you want predictable, steady income without the complexity of reinvestment. A ₹10 lakh fixed deposit at 7% simple interest gives you ₹70,000 per year in interest — ₹17,500 paid quarterly. This predictability helps in planning for regular expenses or meeting annual financial goals. However, for long-term wealth creation, compound interest instruments like equity mutual funds, PPF (which compounds annually), and dividend reinvestment plans are significantly more powerful.