How to use the compound interest calculator
- Enter the principal.
- Enter the annual interest rate and the number of years.
- Choose how often interest is added.
- Press Calculate to see the final amount, the interest and each year's balance.
Compound and simple interest
Simple interest is paid on the original principal only. Compound interest is paid on the principal plus the interest already added, so the gap grows every year. The result shows both on the same numbers.