Simple & Compound Interest Calculator
Our calculator allows the accurate calculation of simple or compound interest accumulated over a period of time.
To use our calculator, simply:
Select the currency from the drop-down list (this step is optional).
Choose what you would like to calculate:
- 1. The simple interest, or
- 2. Compound interest.
Enter the principal amount, interest rate, time period, and click 'Calculate' to retrieve the interest.
Number of Years to Double Investment Chart
Simple interest is calculated only on the principal amount of an investment.
The following formula can be used to find out the simple interest:
- I = P×r×t
- I = amount of interest, P = principal amount, r = annual interest rate, t = time in years.
Compound Interest is calculated on the principal amount and also on the interest of previous periods.
The following formula can be used to find out the compound interest:
- A = P×(1 + r/n) nt
- A = final amount including interest, P = principal amount, r = annual interest rate (as decimal), n = number of compounds per year, t = number of years.