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Tool · Retirement

Retirement contribution projector

Current balance, monthly contribution, expected return, years. The ending number is a guess; the split between contributions and compounding is the part worth looking at. At 30 years and a typical equity return, compounding is usually the larger slice.

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

ContributionsGrowth from returns
$0$1,067,396$2,134,792year 0year 15year 30
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.