Simple Interest Calculator
Calculate simple interest and total amount on any principal, rate, and time period. Includes yearly breakdown.
How to Use the Simple Interest Calculator
- Enter the principal amount (the sum lent, borrowed, or invested).
- Enter the annual interest rate in percent.
- Enter the time period in years (decimals allowed, e.g., 2.5).
- Click Calculate to see interest earned, total amount, and the year-wise table.
Formula & Method
Simple Interest = (P x R x T) / 100
Where P = principal, R = annual rate, T = time in years. Total Amount = P + SI
Unlike compound interest, simple interest never earns interest on interest — growth is linear, so each year adds exactly P x R / 100.
Examples
| Principal | Rate | Time | Interest | Total |
|---|---|---|---|---|
| 10,000 | 8% | 3 yr | 2,400 | 12,400 |
| 50,000 | 6% | 5 yr | 15,000 | 65,000 |
| 100,000 | 12% | 2 yr | 24,000 | 124,000 |
| 25,000 | 10% | 4 yr | 10,000 | 35,000 |
Frequently Asked Questions
What is simple interest?
Simple interest is calculated only on the original principal — interest does not compound. Each period earns exactly the same amount: Principal x Rate x Time / 100.
What is the difference between simple and compound interest?
Simple interest grows linearly; compound interest grows exponentially because each period earns interest on previous interest. Over 10 years at 10%, 10,000 becomes 20,000 with simple interest but 25,937 with annual compounding.
Where is simple interest used in real life?
Short-term loans, some car loans, treasury bills, and certain bonds. Most savings accounts and FDs use compound interest instead.
How do I calculate simple interest per month?
Use T in years as months / 12. For 6 months at 12% on 10,000: 10,000 x 12 x 0.5 / 100 = 600.
Is simple interest better for borrowers?
Yes — borrowers pay less with simple interest than compound interest at the same rate and term, which is why lenders usually prefer compound structures.
🔥 Popular Simple Interest Calculator Results
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People Also Ask
What is the simple interest on 10,000 at 10% for 2 years?
SI = (10,000 x 10 x 2) / 100 = 2,000. Total amount = 12,000.
How do you find the rate when SI, principal, and time are known?
Rearrange the formula: R = (SI x 100) / (P x T). For SI of 2,400 on 10,000 over 3 years: R = 240,000 / 30,000 = 8%.
Does simple interest change every year?
No — the interest earned each year is identical because it is always calculated on the original principal only.