Safe withdrawal rate — three strategies, side by side, net of tax
Most SWR tools show one strategy, one start date, and pretend tax doesn't exist. This rolls fixed real (Bengen), Guyton-Klinger 20/10 guardrails, and a PMT-based (VPW-style) rule across every start year since 1928, then converts gross withdrawals to net-spendable with 2026 IRS brackets — where taxable accounts pay capital-gains tax on the gain portion only. Every output is a range.
Three strategies, one table
all figures are ranges, real (today's) dollars| Fixed real (Bengen) | GK 20/10 guardrails | PMT (VPW-style) |
|---|
Success = the portfolio covers every scheduled withdrawal through the horizon. The PMT-based (VPW-style) rule shows 100% by construction — it withdraws a percentage of whatever is left, so its risk lands in the “lowest real year” row instead. Compare the income-floor row, not just the success row.
Ending balance after the horizon
real $ · p5 · median · p95Fixed real (Bengen)
GK 20/10 guardrails
PMT (VPW-style)
Coral = 5th-percentile, green = median, lime = 95th-percentile ending balance in today's dollars. The PMT-based (VPW-style) rule ends near zero by design — it spends the portfolio down over the horizon rather than leaving a bequest.
Show the math ›
Assumptions & sources ›
| Assumption | Value | Source · asOf |
|---|---|---|
| Equity return | S&P 500 total return | Damodaran (NYU Stern), annual · asOf 2026-01 · dividends reinvested |
| Fixed-income sleeve | 3-month T-bill | Damodaran (NYU Stern) · asOf 2026-01 · more conservative than the intermediate Treasuries in Bengen's study — disclosed, not hidden |
| Inflation | CPI-U, Dec/Dec | BLS · asOf 2026-01 · drives the fixed-real and GK inflation step and all real-dollar output |
| Federal tax, 2026 | brackets + standard deduction | IRS Rev. Proc. 2025-32 · asOf 2025-10 · ordinary tables for traditional, 0/15/20 LTCG for taxable-account gains; withdrawal assumed to be the only income; state tax and NIIT out of scope (v1) |
| Guardrail rules | ±20% band, 10% adjust | Guyton & Klinger, Journal of Financial Planning · asOf 2006-03 · capital-preservation + prosperity rules only; the paper's inflation-cap and portfolio-management rules are omitted for transparency |
| PMT (VPW-style) percentage | p = r / (1 − (1+r)−n) | Bogleheads wiki (PMT formula) · r = geometric-mean real return of your mix over 1928–2025, net of your fee — derived from the dataset, not a forward-looking guess. One deliberate difference from the official Bogleheads VPW table: that tool amortizes against fixed conservative expected real returns (~5% stocks / 1.9% bonds), so its percentages run lower than this historical-r variant |
| Mechanics | start-of-year withdrawal, annual rebalance | coverage 1928–2025; real withdrawals taxed against 2026 tables (the standard “brackets keep pace with inflation” assumption) |
Rolling windows are overlapping start years, so they are not independent samples — a p5 across the windows is an illustrative historical range, not a probability of the future. Sequence risk is the point: the same average return with a bad first decade (1966-style, 2000-style) is what breaks a plan.
Common questions
Is the 4% rule still safe in 2026? ›
The 4% rule comes from the Trinity and Bengen studies of US market history: a 4% first-year withdrawal, then adjusted for inflation, survived 30 years in nearly every historical start year. It is a reference point, not a promise — it assumes a roughly 30-year horizon, a stock-heavy portfolio, and ignores taxes and fees. A longer retirement, high fees, or a poor sequence of early returns can push the sustainable rate below 4%. This calculator replays your inputs across every start year since 1928 and reports a success rate, so you see the range instead of one number.
What is a safe withdrawal rate for a 40-year early retirement? ›
For horizons longer than 30 years, which are common in FIRE, the sustainable fixed rate tends to fall — historical backtests often land near 3.25 to 3.5% — because a longer horizon gives sequence-of-returns risk more time to do damage. The exact figure depends on your asset mix and whether you flex spending in down years. Set the horizon in the calculator to see how the success rate moves.
How much do taxes lower my real withdrawal rate? ›
A 4% headline is a gross figure. In a taxable account you owe tax only on the gain portion of what you sell, at long-term capital-gains rates, not on the whole withdrawal, so the drag is smaller than many people assume. In a Traditional IRA the full withdrawal is ordinary income. The calculator applies a bracket-aware gross-to-net layer by account type, so the spendable number reflects what actually reaches your pocket.
What are Guyton-Klinger guardrails and the PMT-based (VPW-style) rule? ›
They are dynamic strategies that adjust spending to how the portfolio performs instead of paying a fixed inflation-adjusted amount. Guyton-Klinger 20/10 guardrails cut or raise the withdrawal when the current rate drifts too far from target; the PMT-based (VPW-style) rule recalculates each year from the remaining balance and horizon. Unlike the official Bogleheads VPW table, which amortizes against fixed conservative expected real returns (about 5 percent stocks, 1.9 percent bonds), this variant amortizes against the realized historical real return of your chosen mix, so its percentages run higher. Both trade a steadier portfolio survival rate for a more variable paycheck. This page runs all three in parallel.
Related
- Guide: what is a safe withdrawal rate
The 4% study and what moves the number in practice.
- Sequence-of-returns risk
Why the order of returns decides whether money lasts.
- The Roth conversion ladder 5-year rule
The waiting period that decides which dollars an early retiree can actually touch.
- How long will my money last
Depletion age as a range, three engines.
- Methodology
How the backtest engine and data layers are built.