Compound Interest Calculator
See how your savings or investment can grow over time. Enter a principal amount, annual interest rate, compounding frequency and number of years to see the final amount and total interest earned, updated live.
How to Use the Compound Interest Calculator
- Enter your starting principal amount.
- Enter the annual interest rate offered.
- Choose how often interest compounds: annually, semi-annually, quarterly, monthly or daily.
- Enter the number of years you plan to leave the money invested.
- The final amount and total interest earned update instantly, along with a year-by-year growth table.
Why Use This Tool?
How is compound interest calculated?
This tool uses the standard compound interest formula: A = P × (1 + r/n)^(n×t), where P is the principal, r is the annual interest rate (as a decimal), n is the number of compounding periods per year, and t is the number of years. Total interest earned is simply the final amount minus the original principal.
Why does compounding frequency matter?
The more frequently interest compounds, the more often you earn "interest on interest," which slightly increases your final return even at the same nominal annual rate. Daily compounding yields marginally more than monthly, which yields more than annual compounding — though the difference is usually small for typical rates and timeframes.
What does the year-by-year table show?
The table breaks down how your balance grows at the end of each year, so you can see the effect of compounding accelerate over time rather than just the final result. This is useful for visualizing long-term savings or investment goals.
Is this investment advice?
No. This calculator provides a mathematical estimate based on a fixed rate you enter — it does not account for market volatility, fees, taxes or variable returns that real investments typically experience. Results are for general informational purposes only and should not be treated as financial advice. Always consult a qualified financial advisor before making investment decisions.