Compound Interest Calculator

Our Compound Interest Calculator models the exponential wealth accumulation created when interest earns interest over time. Based on the fundamental compound interest equation $A = P\left(1 + \frac{r}{n}\right)^{nt} + PMT \times \left[\frac{\left(1 + \frac{r}{n}\right)^{nt} - 1}{\frac{r}{n}}\right]$, the calculator models initial capital ($P$), annual return rate ($r$), compounding intervals ($n$), investment horizon ($t$), and periodic recurring contributions ($PMT$). It visualizes the compounding curve, distinguishing between your cumulative out-of-pocket deposits and the compound interest generated, making it an essential tool for retirement planning, stock investing, and long-term savings goals.

• Projecting long-term retirement balances in 401(k), IRA, and pension accounts
• Demonstrating the exponential impact of disciplined monthly dollar-cost averaging
• Comparing daily, monthly, and annual compounding frequency differences
• Setting target savings milestones for college funds or down payment savings
• Evaluating the compounding growth of dividend reinvestment programs (DRIP)
• Understanding the dramatic advantage of starting to invest early in life

1. Enter your starting deposit amount (principal). 2. Input your projected annual rate of return (interest rate). 3. Choose your investment timeframe in years. 4. Specify compounding frequency (such as monthly or annually). 5. Optionally add a recurring contribution amount made at regular intervals. 6. Inspect the future investment balance and total compound gains.