Compound Growth & Dollar-Cost Averaging Calculator
Enter a starting amount, a monthly contribution, a time horizon, and an expected annual return to see how much of your ending balance comes from contributions vs. growth.
Your inputs
Your results
Year-by-year breakdown
| Year | Contributed to date | Balance |
|---|
How this is calculated
We apply your expected annual return as a monthly rate (annual ÷ 12) and add your monthly contribution at the end of each month, compounding on the running balance. This models dollar-cost averaging: you invest the same amount on a fixed schedule regardless of market conditions. Actual returns vary year to year — this tool assumes a constant average rate for simplicity.
Why the growth line accelerates
Early on, most of your balance is what you put in. Over time, growth compounds on itself and can outpace new contributions — which is why starting early, even with small amounts, tends to matter more than trying to time the market later.