Withdrawal rate calculator: would your plan have survived every market since 1928?

By Tom, CPA · Updated October 25, 2026

TL;DR: Enter your portfolio, first-year spending, stock/bond mix, horizon and fees. The calculator replays every historical starting year from 1928 using S&P 500 and 10-year Treasury returns plus CPI inflation, and reports how often the money lasted. It's a history lesson, not a forecast.

Educational only, not tax, legal, or investment advice. Examples are illustrations, not predictions. Rules and limits change; verify current figures and talk to a qualified professional about your situation.

Lavish Larry's withdrawal plan is "4%, because the internet." Frugal Fran's plan is "let me test 4% against the Great Depression, the 1966 stagflation decade, and 2000 to 2009, and then decide." This calculator is for Fran, and for Larry once he has calmed down.

It backtests a constant inflation-adjusted withdrawal, the same method behind the classic research covered in safe withdrawal rate research.

CPA Warning Label: Historical success is not a promise. The future will be one path that hasn't happened yet, and US returns over the past century were unusually good by global standards.

Inputs

• Starting portfolio: investable assets you'll draw from, excluding home equity and emergency cash.
• First-year withdrawal: what you'll take in year one. Each later year, the dollar amount rises with actual historical inflation, so purchasing power stays constant.
• Stock allocation: the percentage in US large-cap stocks (S&P 500 with dividends). The rest is in 10-year US Treasury bonds. The portfolio is rebalanced to this mix every year.
• Retirement length: up to 60 years. Early retirees should test 40 to 60.
• Annual fees: fund expense ratios plus any advisory fee, deducted from the portfolio every year. See the expense ratio fee calculator.

Mechanics: each year the withdrawal is taken at the start, the remainder earns that year's blended return, fees are deducted, and spending is inflated by that year's CPI change. A period "fails" if a withdrawal can't be fully paid.

Embedded historical return series (sourced)

The tool embeds 98 years of annual data, 1928 through 2025:

For example, the dataset shows the S&P 500 at -43.84% in 1931 and +24.88% in 2024, while 10-year Treasuries returned -1.64% in 2024. Rolling 30-year periods starting 1928 through 1996 give 69 complete histories. Rolling 50-year periods give 49.

Success rate output

• Initial withdrawal rate: first-year spending divided by the portfolio.
• Historical success rate: the share of starting years in which every withdrawal was paid in full for the whole horizon.
• Periods tested: how many complete historical windows fit. Longer horizons mean fewer, more overlapping windows, so each one carries more weight.
• Worst starting year: the start year with the lowest ending real balance, or the earliest one that ran out among the ties at zero. Usually it's around 1929, the mid-1960s, or 1937.
• Median ending balance: in starting-year dollars. A high median with a low success rate is the signature of sequence risk: most paths end rich and a few end broke.

How to read a borderline result

A 90% historical success rate doesn't mean a 10% chance of ruin. It means a few specific historical sequences, usually a crash or a decade of high inflation early on, broke the plan. Ask yourself what you would have done in those years. If the answer is "cut travel and pick up some part-time work," a plan that fails only in rigid backtests may be perfectly livable.

Limits

• US-only and only two assets. No international stocks, small caps, TIPS or cash. Pfau's 2010 international research found US history unusually kind; see the research page.
• No flexibility. Real retirees cut spending in bad years. See the guardrails calculator.
• No taxes, Social Security, pensions or one-time expenses.
• Annual data. Within-year crashes and the exact timing of withdrawals aren't modeled.
• Different from published studies. Bengen used intermediate-term government bonds and his own conventions; Trinity used corporate bonds. Using 10-year Treasuries and start-of-year withdrawals, a 4% plan at 60% stocks over 30 years succeeds in 94.2% of periods here, not 100%. Small methodology choices move the edge cases.

Example

Illustration: Fran has $1,000,000 and wants $40,000 in year one, a 4.0% rate.

Two lessons jump out. Stretching the horizon from 30 to 50 years hurts more than most people expect, and a 1% annual fee damages a plan about as much as a big jump in spending. Pair results with the guardrails guide and rebalancing calculator, and check costs with the rental cash flow calculator if real estate is part of your income plan.