Simple Interest Calculator
Calculate simple interest using SI = P × R × T / 100. Enter principal, rate & time.
Quick Reference — SI on ₹10,000
| Rate | 1 Year | 3 Years | 5 Years |
|---|---|---|---|
| 5% | 500.00 | 1,500.00 | 2,500.00 |
| 8% | 800.00 | 2,400.00 | 4,000.00 |
| 10% | 1,000.00 | 3,000.00 | 5,000.00 |
| 12% | 1,200.00 | 3,600.00 | 6,000.00 |
| 15% | 1,500.00 | 4,500.00 | 7,500.00 |
Understanding Simple Interest
Simple interest is the most straightforward way to calculate interest on a loan or investment. Unlike compound interest, it's calculated only on the original principal — the interest doesn't earn interest.
The formula is SI = P × R × T / 100, where P is the principal amount, R is the annual interest rate (%), and T is the time in years. The total amount you receive or owe is A = P + SI.
Simple Interest vs. Compound Interest
With simple interest, ₹10,000 at 10% for 5 years earns ₹5,000 in interest. With compound interest (annual compounding), the same investment earns ₹6,105. The difference grows dramatically over longer periods — making compound interest the "eighth wonder of the world."