Tool · Retirement
Retirement contribution projector
Four inputs, one chart. The point isn't the precise ending number — that's a function of an unknowable future return — but the share of the final balance that came from compounding rather than from contributions. For a 30-year horizon at a reasonable equity return, compounding almost always carries the larger share, and that band is what the chart makes visible.
Projected ending balance
$2,134,792
After 30 years at 7.0% annual
What you contributed
$590,000
$50,000 start + $540,000 added
What compounding added
$1,544,792
72% of the ending balance
How this is calculated
Each month, the balance earns one month's compounded return at the annual rate you entered, then the monthly contribution is added. Inflation, if enabled, is applied at the end as a simple deflator: real = nominal / (1 + inflation)^years.
The chart stacks two bands so the compounding punchline is visible: the lower (grey) area is what you actually contributed; the upper (green) area is what compounding added on top. For long horizons the green area dominates — that's the whole reason starting early matters.
The return rate is your input, not a prediction. 7% nominal sits inside the historical range for a diversified US equity portfolio, but any single 30-year window can land substantially above or below. Sequence-of-returns risk (the order in which good and bad years land) can shift the actual outcome materially even when the average return matches.
Taxes, fees, employer matches, contribution-limit caps, and Social Security are not modelled. Use the expense-ratio cost calculator to see how fund fees eat into the green band over the same horizon.
Illustrative projection. Not personalized investment advice and not a forecast of any specific account's outcome.
Constant-rate projection. Real markets deliver variable returns, and the order of those returns (sequence-of-returns risk) can shift the realized outcome even when the long-run average is identical. Don't anchor on the ending dollar figure.
PlainIndex publishes data and editorial commentary — nothing here is personalized investment advice. Confirm any plan that depends on a specific projection with a fee-only advisor whose compensation isn't tied to product sales.