Compound Interest Calculator
See how your money grows over time with the power of compound interest.
Future Value
Total value of your investment after the selected period.
How compound interest works
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. It's often called "interest on interest" and is the reason why starting to invest early matters so much.
The compound interest formula
A = P(1 + r/n)^(nt) where P = principal, r = annual rate, n = compounding frequency, and t = time in years. When you add regular contributions, each deposit also compounds for its remaining time.
Why compounding frequency matters
The more frequently interest compounds, the more you earn. Daily compounding produces slightly more than monthly, which produces more than annually. However, the difference is small compared to the impact of rate and time.
The power of time
Because compound interest grows exponentially, time is your greatest advantage. Starting 10 years earlier can double your final balance even with the same contributions, thanks to the snowball effect of compounding.