Every retirement since 1872: the data behind InvestWealth's withdrawal calculators
Annual US data from 1872 to 2025 and a small Python script that reproduce the numbers on
investwealth.com/tools/safe-withdrawal-rate and
investwealth.com/tools/how-long-will-my-money-last:
- At a 4% first-year withdrawal, raised with inflation every year, a 60/40 portfolio lasted 30 years in 124 of 125 retirement starts since 1872. The one failure started in 1966.
- The highest rate that survived every 30-year start was 3.9% with 60% stocks (4.0% with 80%); for 40 years about 3.6%; the cautious 20/80 mix fell to 2.7% over 40 years and 2.3% over 50.
- The eight worst 30-year start years all lie between 1962 and 1973, when bonds stopped cushioning stocks; the best (for example 1921 and 1982) supported 9–10%.
Backtested results are hypothetical. Educational research, not investment advice.
Data
data/us_annual_returns_1872.csv — one row per calendar year, 1872–2025:
| column | meaning |
|---|
us_stocks_total_return | US stocks (S&P 500 and its predecessors), total return, decimal (0.10 = +10%) |
us_10y_treasury_total_return | 10-year US Treasury, total return |
us_cpi_inflation | US consumer price inflation |
Sources: Robert Shiller's long-run stock, interest-rate and CPI series (Yale, "Irrational Exuberance" data) and FRED (Federal Reserve Bank of St. Louis); InvestWealth calculations for the annual total returns. Use the data freely with attribution to the original sources and to InvestWealth.com.
Script
python scripts/retirement_test.py # 60/40, 4%, 30 years, plus the tables
python scripts/retirement_test.py --stocks 80 --rate 3.5 --years 40 --fee 0.2
No dependencies beyond the Python standard library. The method is the one the calculators use: stocks and 10-year Treasuries rebalanced
once a year, the withdrawal raised with each year's actual inflation, one retirement starting in every year from 1872, before taxes,
optional yearly cost in percent.
Sample output (defaults):
4.00% withdrawal, 60/40, 30 years, costs 0.00%: 124 of 125 retirement starts (1872–1996) survived
failures: 1966 (ran out in year 29)
highest rate that survived every start: 3.91%
Safe maximum withdrawal rate by mix and horizon (survived every start since 1872):
stocks/bonds 20y 30y 40y 50y
100/0 4.5% 3.9% 3.7% 3.6%
80/20 4.7% 4.0% 3.8% 3.6%
60/40 4.8% 3.9% 3.6% 3.5%
40/60 4.7% 3.8% 3.5% 3.1%
20/80 4.5% 3.4% 2.7% 2.3%
More from InvestWealth
Licence
Code: MIT (see LICENSE). Data: derived from the public Shiller and FRED series, free to use with attribution.
InvestWealth.com · Dr.-Ing. Harry Hamann · Educational research, not investment advice. Past returns do not guarantee future results. Backtested results are hypothetical.
