Interest Calculator
Calculate simple interest and the total amount on a principal over a number of years.
Runs in your browser Your input never leaves your device.
About this tool
Enter a principal, an annual interest rate and a time in years to calculate simple interest. Simple interest is calculated only on the original amount: interest = principal x rate x time / 100. The tool shows the interest and the total amount, which is the principal plus the interest. Time is in years, so convert months by dividing by 12 (6 months is 0.5). Because interest does not compound, use the compound interest calculator if interest is added to the balance as it accrues. Results are general estimates, not financial advice, and are formatted to two decimal places. All calculation runs in your browser.
How to use it
- Enter the principal amount.
- Enter the yearly interest rate as a percentage.
- Enter the time in years.
- Read the interest and the total amount.
Example
5000 x 4 x 3 / 100 = 600.
5,000 at 4% for 3 years
Interest: 600.00 Total amount: 5,600.00
Common problems
- No result is shown
- The principal must be greater than zero.
- The figure is lower than my savings account shows
- Savings accounts usually compound. Simple interest ignores interest on interest.
- Time in months
- Time must be entered in years. Divide months by 12.