Compound Interest Calculator
See how your investment grows with the power of compounding
Investment Details
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Growth Summary
Enter investment details to see growth summary
Year-by-Year Growth
Year-by-year breakdown will appear here
About Compound Interest
Compound interest is interest calculated on the initial principal AND the accumulated interest from previous periods. It's often called the "eighth wonder of the world" because of its exponential growth potential over time.
Formula
A = P(1 + r/n)^(nt)
A = Final amount
P = Principal
r = Annual interest rate (decimal)
n = Compounding frequency per year
t = Time in years
Key Insights
- More frequent compounding = slightly higher returns
- Time is the most powerful factor in compounding
- Regular contributions dramatically increase final balance
- Rule of 72: divide 72 by rate to estimate doubling time