Compound Interest Calculator
See how compound interest grows your investment over time with customizable compounding frequency.
Optional
Compound Interest Results
How to Use the Compound Interest Calculator
- Enter your initial principal.
- Set the annual interest rate.
- Choose compounding frequency (monthly is typical for savings accounts).
- Optionally add a monthly contribution to see regular investing results.
Formula
A = P(1 + r/n)^(nt)Where P = principal, r = rate, n = compounds/year, t = years
Frequently Asked Questions
What is compound interest?
Compound interest means you earn interest on your interest, not just the original principal. This leads to exponential rather than linear growth.
How often does compound interest compound?
Savings accounts typically compound daily or monthly. The more frequently it compounds, the higher your effective annual yield (APY).
What is the Rule of 72?
Divide 72 by your annual interest rate to estimate how many years it takes to double your money. At 7%, money doubles in ~10.3 years.
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