Free compound interest calculator. Enter principal, rate, time and compounding frequency to see how your money grows. Shows monthly breakdown.
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Compound Interest Calculator
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Formula
Formula
A = P(1 + r/n)^(nt)
A = Final amount · P = Principal · r = Annual rate (decimal) · n = Times compounded per year · t = Years. Example: $10,000 at 8% for 10 years monthly = $22,196.
Frequently Asked Questions
What is compound interest?+
Compound interest is interest calculated on both the initial principal and the accumulated interest. Unlike simple interest, it grows exponentially over time.
How often should interest compound?+
More frequent compounding = slightly more growth. Daily compounding earns marginally more than monthly, which earns more than annual.
What is the Rule of 72?+
Divide 72 by annual interest rate to estimate years to double. At 8% interest: 72/8 = 9 years to double your money.