About Simple Interest Calculator
The Simple Interest Calculator calculates interest on the principal only—no compounding. Interest is computed on the original amount throughout the tenure. It is common in short-term loans, certain deposits, and quick estimations.
While most modern banking uses compound interest, understanding simple interest is essential for comparing loan offers, some government schemes, and the fundamentals of interest math.
Formula
Total Amount = P + SI
Where:
P = Principal amount
R = Rate of interest (% per annum)
T = Time period in years
SI = Simple interest earned
Example
Example: For a principal amount of ₹1,00,000 at 8% interest for 3 years, the simple interest is ₹24,000. Using the formula, SI = (1,00,000 � 8 � 3) / 100 = ₹24,000. Therefore, the total amount = ₹1,00,000 + ₹24,000 = ₹1,24,000, which matches the calculator result shown above.
Common Uses
Short-term personal loans (6–12 months), some auto loans, informal lending, certificates of deposit, quick estimates, educational examples.
Simple vs Compound
Same ₹1,00,000 @10% for 5 years: Simple = ₹1,50,000 total (₹50,000 interest). Compound = ₹1,61,000 (₹61,000 interest). Compound gives ~₹11,000 more. Use SI for short tenures and quick estimates; use compound for FDs, PPF, and investments.