1
Enter Principal
Input your initial investment amount.
Compound Interest Calculator
Calculate exponential investment growth over time
Pro Tip
The Rule of 72 estimates doubling time: divide 72 by interest rate. At 8% annual return, your money doubles in ~9 years.
How to Use the Compound Interest Calculator
2
Set Rate & Time
Enter interest rate and investment duration.
3
View Growth
See how compound interest grows your investment over time.
The Power of Compounding
Compound interest is exponential growth where you earn interest on interest. Time and consistency are more powerful than large lump sums.
Frequently Asked Questions
Compound interest is interest calculated on initial principal plus accumulated interest from previous periods.
More frequent compounding (daily vs. annually) increases returns. Daily compounding is optimal.