Compound Interest Calculator
Calculate compound interest growth with yearly breakdown and multiple compounding frequencies.
Compound Interest Calculator
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How to Use
- Enter the initial principal (starting amount).
- Set the annual interest rate and select how often it compounds.
- Enter the investment period in years.
- Optionally add regular contributions (monthly or yearly).
- Results and the year-by-year table update instantly.
Frequently Asked Questions
QWhat is compound interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Unlike simple interest, it grows exponentially over time.
QHow does compounding frequency affect growth?
The more frequently interest compounds, the more you earn. Daily compounding earns slightly more than monthly, which earns more than annual — though the difference shrinks at lower rates.
QWhat is the Rule of 72?
Divide 72 by the annual interest rate to estimate how many years it takes to double your investment. At 8% interest, your money doubles in roughly 72 ÷ 8 = 9 years.
QWhat is the difference between APR and APY?
APR (Annual Percentage Rate) is the nominal rate. APY (Annual Percentage Yield) accounts for compounding within the year — it is always equal to or higher than APR.
About This Calculator
Uses the standard compound interest formula: A = P(1 + r/n)^(nt). For regular contributions, each contribution is compounded from the point it is made to the end of the period.