The calculator
Run your birth month.
A pooled fund’s math, not a personal account — 155 years of real market history, and your inputs never leave your device.
Fine print and method
The fine print
Educational illustration — not investment advice, not a prediction. These figures are a hypothetical illustration of mathematical compounding using the historical S&P Composite index (Robert J. Shiller’s public dataset, shillerdata.com). You cannot invest directly in an index; results exclude all fees, taxes, and costs; broad index funds did not exist before 1976. Past performance does not guarantee or predict future results — other countries’ markets, and other time periods, have done far worse. Every figure here is in the dollars of its own year, with no inflation adjustment. Figures beyond January 2026 use an assumed 9.36% average return; the actual future will differ, possibly dramatically. The Social Security figure is a simplified estimate of the scheduled benefit under current law for a hypothetical lifelong average earner — your own benefit depends on your earnings record (see ssa.gov); under current projections, full scheduled benefits are payable only until trust-fund depletion (2026 Trustees Report). This site is not affiliated with the Social Security Administration and is not a broker-dealer or investment adviser.
How this is calculated
Check our math. Three cases our test suite pins against the raw data, every time it runs: $1 in January 1960 became $470.42 by January 2022 · $250 at a 1990 birth became $10,359.02 by January 2026 · $50 a month from 1980 through 2019 — $24,000 in — became $361,333.17. Every figure is nominal, in the dollars of its own year.
Honest limits
Read this before you quote the number.
Past returns don’t promise future ones. This models a pooled fund, not an account you’d own. It ignores fees and taxes. And Social Security today still pays about 81 cents of every scheduled dollar after 2033 even if nothing changes — the calculator shows the size of the missed opportunity, not a prediction of your check.
More on what stays true either way: Objections & rebuttals · Why this is not privatization
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Still a pension — just funded better. Send someone their own birth month’s math.