Simple Interest Calculator India RBI Guidelines 2025

Simple Interest (SI) is calculated as SI = (P × R × T) / 100, where P = Principal, R = Rate of Interest (% per annum), and T = Time in years. This flat-rate method is used for NSC (National Savings Certificate), some personal loans, and certain term deposits — though most modern bank products use compound interest.

For a ₹1 lakh investment at 7.5% for 3 years: SI = (100000 × 7.5 × 3) / 100 = ₹22,500. Total at maturity = ₹1,22,500.

SI vs EMI: Know the Difference

Simple Interest treats interest as a fixed amount on the original principal. EMI (Equated Monthly Instalment) loans use reducing balance — interest is recalculated on the outstanding principal each month. EMI loans cost less in total interest than flat-rate loans at the same stated rate.

Use our simple interest calculator india rupees for flat-rate calculations. For EMI-based loans, use our emi calculator india loan. To understand your marks: marks percentage calculator india.