Calculate simple interest, or solve for the rate, time or principal.
Interest = Principal × Rate × Time. ₹1,00,000 at 8% for 3 years earns ₹24,000.00 of simple interest, for a total of ₹1,24,000.
Simple interest is calculated only on the original amount, not on interest already earned, so it grows in a straight line. Choose what you want to find — the interest, the rate, the time or the principal — and enter the other values. Time can be in years, months or days.
Simple interest is common in short-term loans, some bonds and school maths. For interest that also earns interest, use the Compound Interest Calculator. To see how a fixed deposit compounds, try the CD Calculator.
The calculator applies the standard financial formulas step by step.
| Item | Value |
|---|---|
| Principal | ₹1,00,000.00 |
| Interest rate | 8% per year |
| Time | 3 years (36 months, 1,095 days) |
| Interest | ₹24,000.00 |
| Total (principal + interest) | ₹1,24,000.00 |
| Scenario | Interest |
|---|---|
| ₹1,00,000 at 8% for 1 year | ₹8,000.00 |
| ₹1,00,000 at 8% for 3 years | ₹24,000.00 |
| ₹1,00,000 at 8% for 5 years | ₹40,000.00 |
| ₹1,00,000 at 8% for 180 days | ₹3,945.21 |
| ₹1,00,000 at 12% for 3 years | ₹36,000.00 |
I = P × R × T, with the rate expressed as a decimal (or divided by 100) and time in years.
Convert the period to years: months ÷ 12 or days ÷ 365.
Simple interest is only on the principal; compound interest is on the principal plus accumulated interest, so it grows faster.
Short-term personal loans, some car loans, certain bonds and many textbook problems.
Rate = interest ÷ (principal × time) × 100. Select “Interest rate” in the calculator.
Years = 100 ÷ rate. At 8% simple interest it takes 12.5 years.
It uses the standard formula: I = P × R × T ÷ 100 A = P + I The full method and a worked example are shown on this page.
No. The calculator gives estimates for planning and learning. Real offers vary by lender, product and date, so confirm the details with your bank, lender or a qualified adviser before deciding.
Yes. The maths is identical in any currency; only the currency symbol shown in the results differs.
No. Everything is calculated in your browser and nothing you enter is uploaded or saved.
