Senior · Withdrawal

Is your withdrawal rate safe?

4% rule, Bengen 1994, Trinity 1998 — your portfolio + allocation tested against historical 30-year success rates.

Inputs

Portfolio balance (USD)

First-year withdrawal (USD) 4% of $1M = $40K.

Years in retirement

% Stocks Rest in bonds.

Inflation %

Initial withdrawal rate

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Historical success probability

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Ending balance (real $, projected)

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Success rate is approximated from Bengen 1994 + Trinity 1998 success-rate charts for 75/25 stock/bond. Different studies vary ±5% by methodology.
Sequence-of-returns risk: a bad first 5 years can derail even a "safe" rate. Consider a dynamic guardrail (Guyton-Klinger) if early returns are weak.
Taxes, fees, and longevity insurance not modeled. Morningstar 2024 suggests current valuations argue for ~3.7% to maintain historical safety.
Real-dollar ending balance assumes user-supplied inflation rate (default 3%) — actual CPI varies year to year.

How this is calculated

Success table — 75/25 portfolio, 30-yr horizon: 3% → 100%, 3.5% → 99%, 4% → 96%, 4.5% → 86%, 5% → 72%, 5.5% → 53%, 6% → 38%, 7% → 18%. Linear interpolation between points.
Real return mix: 7% stocks, 1.5% bonds (long-run US data). Nominal return = (1 + real)(1 + inflation) − 1.
Year-by-year: balance grows at nominal return, withdrawal grows at inflation.
Sources: Bengen 1994 + Trinity 1998 (cross-checked Bestinterest.blog 2024 update + Morningstar 2024). Last reviewed 2026-05-22.