How compound interest works
Compound interest estimates how a balance can grow when earnings stay invested. Each compounding period adds interest to the balance, so the next period starts from a slightly larger amount. Regular monthly contributions can make the effect more meaningful because each contribution receives time to grow.
Using this calculator
Enter your current investment, the amount you expect to add each month, an annual return assumption, and your time horizon. The projection separates the money you put in from estimated interest, making the trade-off between saving more and waiting longer easier to see.
Keep the assumptions realistic
This is a planning tool, not a promise. Markets change, fees and taxes can reduce returns, and a fixed annual rate is only an illustration. Compare a few conservative scenarios before using the estimate in a financial decision.