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Separate money you contribute from modeled interest. Explore how a starting balance and regular monthly deposits grow over time.
02 / The result
Showing the editable example above. Modeled values, not a forecast.
Of the ending balance, USD 34,000.00 is money contributed and USD 13,526.55 is modeled growth. Recalculate with a lower rate to see how much of the goal depends on returns. Use a net rate after recurring investment costs if appropriate; this model does not subtract fees separately.
Before interpreting the result
The entered rate is nominal annual interest compounded monthly. Deposits occur at month end. Rates and deposits stay constant; taxes, fees, withdrawals and market volatility are excluded. This is not a return forecast.
Monthly rate r = annual nominal rate / 12. Each month: balance = previous balance × (1 + r) + deposit.
Background reading: Investor.gov: compound interest and regular contributions. These references explain the concepts; they do not endorse this calculator.
03 / Visual evidence
Vertical scale: USD. Horizontal scale: Year. Lines join the calculated points; no probability is implied.
Shared value scale; zero is included. These are modeled scenarios using your assumptions, not observed market data. The table provides every plotted value.
USD amounts are displayed to two decimal places. Calculations use unrounded internal values. Scroll across a wide table on smaller screens.
| Year | Projected balance (USD) | Total contributed (USD) | Modeled interest (USD) |
|---|---|---|---|
| 0 | 10,000.00 | 10,000.00 | 0.00 |
| 1 | 12,967.39 | 12,400.00 | 567.39 |
| 2 | 16,086.60 | 14,800.00 | 1,286.60 |
| 3 | 19,365.39 | 17,200.00 | 2,165.39 |
| 4 | 22,811.93 | 19,600.00 | 3,211.93 |
| 5 | 26,434.80 | 22,000.00 | 4,434.80 |
| 6 | 30,243.03 | 24,400.00 | 5,843.03 |
| 7 | 34,246.09 | 26,800.00 | 7,446.09 |
| 8 | 38,453.96 | 29,200.00 | 9,253.96 |
| 9 | 42,877.11 | 31,600.00 | 11,277.11 |
| 10 | 47,526.55 | 34,000.00 | 13,526.55 |
Change one assumption at a time, then compare the result. A scenario is a way to examine a decision, not a promise of an outcome.
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