Compound Interest Calculator
Estimate how your money can grow over time with compound interest.
Investment Growth Chart
About This Compound Interest Calculator
Compound interest allows money to grow by earning returns on both the original amount and previously accumulated interest. Over long periods, this effect can become increasingly powerful. Our Compound Interest Calculator helps you estimate how an initial investment and regular monthly contributions could grow over time.
Enter your starting investment, expected annual interest rate, monthly contribution, investment period, and compounding frequency. The calculator estimates the future balance and separates the result into your total contributions and the estimated interest earned.
For example, a person who starts with an initial investment and continues adding money every month may accumulate significantly more than someone who makes only a one-time deposit. The actual result depends on the investment return, contribution amount, time period, and compounding assumptions.
Compounding frequency determines how often interest is added to the account under the mathematical model. Monthly compounding, quarterly compounding, and annual compounding can produce slightly different results when all other assumptions remain constant.
Investment returns are not guaranteed. Stock market investments, mutual funds, exchange-traded funds, and other assets can rise or fall in value. The calculator uses a constant assumed rate for illustration and should not be interpreted as a prediction of future investment performance.
The interactive chart makes the concept easier to understand by showing the estimated balance increasing over the selected period. You can change the starting amount, monthly contribution, rate, or time period and immediately see how the projected growth changes.
This calculator is intended for educational and financial planning purposes. It does not provide investment advice or guarantee a specific return.