Simple Interest Calculator — Interest from Principal, Rate, Time
CalculatorA simple interest calculator finds interest and the maturity amount when interest accrues on the principal only.
What is it
Simple interest is charged on the principal only, never on previously earned interest. It is calculated in one step as principal × annual rate × years. Over long periods it grows less than compound interest at the same rate, so the result also shows the annually compounded value for comparison.
How to use
- 1Enter the principal.
- 2Enter the annual rate (%) and the number of years.
- 3Check the simple interest, maturity amount, and the compound comparison.
Reference
| Principal | Rate | Years | Simple interest | Maturity |
|---|---|---|---|---|
| 1000000 | 5% | 3 | 150000 | 1150000 |
| 5000000 | 4% | 2 | 400000 | 5400000 |
| 1000000 | 5% | 10 | 500000 | 1,500,000 (compound 1,628,895) |
Sources & standards
- Simple Interest - Wolfram MathWorld
- Compound interest calculator - U.S. SEC Investor.gov
FAQ
What is the simple interest on 1,000,000 at 5% for 3 years?
1,000,000 × 5% × 3 = 150,000, so the maturity amount is 1,150,000.
What is the difference between simple and compound interest?
Simple interest accrues on the principal only, while compound interest also earns interest on prior interest. At 5% for 10 years, 1,000,000 becomes 1,500,000 with simple interest but about 1,628,895 with annual compounding.
Is simple interest calculator input sent to a server?
No. This tool runs in your browser and does not send input to a server.