Plan inputs
Retirement Risk
Retirement Backtest Calculator
Replay your withdrawal plan against every rolling start year of historical stock and bond returns, from a fixed public dataset.
Historical backtestRolling start yearsStock/bond mixFixed data snapshot
Data source: NYU Stern / Aswath Damodaran, "Historical Returns on Stocks, Bonds and Bills: 1928-2025" (updated January 2026).
Backtest results
Success rate
97.1%
Successful windows
67/69
Median ending balance
$5,510,034
Worst surviving outcome
$240,302
Best outcome
$18,045,100
Failing start years
1929, 1930
All rolling windows
| Start year | End year | Ending balance | Total withdrawn | Outcome |
|---|---|---|---|---|
| 1928 | 1957 | $240,302 | $1,903,017 | Survived |
| 1929 | 1958 | $0 | $1,201,249 | Failed in year 22 |
| 1930 | 1959 | $0 | $1,500,523 | Failed in year 26 |
| 1931 | 1960 | $1,187,873 | $1,903,017 | Survived |
| 1932 | 1961 | $6,064,813 | $1,903,017 | Survived |
| 1933 | 1962 | $6,815,134 | $1,903,017 | Survived |
| 1934 | 1963 | $4,597,179 | $1,903,017 | Survived |
| 1935 | 1964 | $5,470,039 | $1,903,017 | Survived |
| 1936 | 1965 | $3,139,757 | $1,903,017 | Survived |
| 1937 | 1966 | $1,594,529 | $1,903,017 | Survived |
| 1938 | 1967 | $5,053,986 | $1,903,017 | Survived |
| 1939 | 1968 | $3,837,687 | $1,903,017 | Survived |
| 1940 | 1969 | $3,973,908 | $1,903,017 | Survived |
| 1941 | 1970 | $5,407,545 | $1,903,017 | Survived |
| 1942 | 1971 | $8,011,684 | $1,903,017 | Survived |
| 1943 | 1972 | $7,876,243 | $1,903,017 | Survived |
| 1944 | 1973 | $5,979,029 | $1,903,017 | Survived |
| 1945 | 1974 | $4,384,023 | $1,903,017 | Survived |
| 1946 | 1975 | $3,778,352 | $1,903,017 | Survived |
| 1947 | 1976 | $5,510,034 | $1,903,017 | Survived |
| 1948 | 1977 | $5,414,920 | $1,903,017 | Survived |
| 1949 | 1978 | $5,634,118 | $1,903,017 | Survived |
| 1950 | 1979 | $5,416,826 | $1,903,017 | Survived |
| 1951 | 1980 | $4,951,495 | $1,903,017 | Survived |
| 1952 | 1981 | $4,118,419 | $1,903,017 | Survived |
| 1953 | 1982 | $4,450,690 | $1,903,017 | Survived |
| 1954 | 1983 | $5,534,289 | $1,903,017 | Survived |
| 1955 | 1984 | $3,416,620 | $1,903,017 | Survived |
| 1956 | 1985 | $2,998,051 | $1,903,017 | Survived |
| 1957 | 1986 | $3,818,448 | $1,903,017 | Survived |
| 1958 | 1987 | $4,948,759 | $1,903,017 | Survived |
| 1959 | 1988 | $3,331,425 | $1,903,017 | Survived |
| 1960 | 1989 | $4,086,941 | $1,903,017 | Survived |
| 1961 | 1990 | $4,166,670 | $1,903,017 | Survived |
| 1962 | 1991 | $3,627,785 | $1,903,017 | Survived |
| 1963 | 1992 | $5,198,333 | $1,903,017 | Survived |
| 1964 | 1993 | $4,495,149 | $1,903,017 | Survived |
| 1965 | 1994 | $3,614,101 | $1,903,017 | Survived |
| 1966 | 1995 | $4,414,533 | $1,903,017 | Survived |
| 1967 | 1996 | $6,995,334 | $1,903,017 | Survived |
| 1968 | 1997 | $6,970,171 | $1,903,017 | Survived |
| 1969 | 1998 | $8,044,051 | $1,903,017 | Survived |
| 1970 | 1999 | $12,218,532 | $1,903,017 | Survived |
| 1971 | 2000 | $11,453,099 | $1,903,017 | Survived |
| 1972 | 2001 | $9,320,012 | $1,903,017 | Survived |
| 1973 | 2002 | $7,359,543 | $1,903,017 | Survived |
| 1974 | 2003 | $11,418,532 | $1,903,017 | Survived |
| 1975 | 2004 | $18,045,100 | $1,903,017 | Survived |
| 1976 | 2005 | $14,179,207 | $1,903,017 | Survived |
| 1977 | 2006 | $12,100,349 | $1,903,017 | Survived |
| 1978 | 2007 | $15,099,431 | $1,903,017 | Survived |
| 1979 | 2008 | $13,213,525 | $1,903,017 | Survived |
| 1980 | 2009 | $13,282,446 | $1,903,017 | Survived |
| 1981 | 2010 | $12,312,660 | $1,903,017 | Survived |
| 1982 | 2011 | $14,116,071 | $1,903,017 | Survived |
| 1983 | 2012 | $11,758,275 | $1,903,017 | Survived |
| 1984 | 2013 | $11,707,375 | $1,903,017 | Survived |
| 1985 | 2014 | $12,273,387 | $1,903,017 | Survived |
| 1986 | 2015 | $8,734,169 | $1,903,017 | Survived |
| 1987 | 2016 | $7,199,501 | $1,903,017 | Survived |
| 1988 | 2017 | $8,689,513 | $1,903,017 | Survived |
| 1989 | 2018 | $7,340,160 | $1,903,017 | Survived |
| 1990 | 2019 | $6,302,720 | $1,903,017 | Survived |
| 1991 | 2020 | $7,859,716 | $1,903,017 | Survived |
| 1992 | 2021 | $6,455,468 | $1,903,017 | Survived |
| 1993 | 2022 | $4,924,619 | $1,903,017 | Survived |
| 1994 | 2023 | $5,021,489 | $1,903,017 | Survived |
| 1995 | 2024 | $6,628,387 | $1,903,017 | Survived |
| 1996 | 2025 | $4,617,821 | $1,903,017 | Survived |
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About this calculator
Method, formulas, and limits.What this does
Runs one rolling simulation per feasible start year in a fixed 1928-2025 stock and bond return dataset, reporting how often each historical sequence funded the full withdrawal plan.
Who it is for
People stress-testing a withdrawal rate against past market histories rather than a single average-return projection.
How it works
Each window applies the blended annual stock/bond return to the remaining balance, then subtracts that year's withdrawal. Withdrawals can rise with an entered inflation rate, and a window fails when a requested withdrawal exceeds the available balance.
Limitations
Backtests describe past sequences only. The model uses annual returns with rebalancing back to the chosen mix, excludes taxes, fees, cash flow timing within the year, social security income, dynamic spending rules, and future prediction entirely.
Key calculations
- Blended annual return
- return = stockWeight × stockReturn + bondWeight × bondReturn
- Inflation-adjusted withdrawal
- withdrawalInYearN = firstWithdrawal × (1 + inflation)^(N − 1)
- Success condition
- every requested withdrawal ≤ portfolio balance after growth
Reference ranges
- Classic reference point
- The original 4% research used U.S. historical data over roughly 30-year retirements, which this tool reproduces directly on its own dataset instead of quoting a result.
- Data window coverage
- A 30-year horizon uses every start year from 1928 through 1996 because later windows would not have full data yet.
- Annual timing note
- Using yearly steps ignores ordering inside the year, so results differ from monthly-balance studies on purpose.
How to use it
- 1.Enter the planProvide the starting portfolio, first-year withdrawal, and retirement horizon.
- 2.Choose the asset mixSet the stock allocation; the remainder is invested in 10-year Treasury bonds and rebalanced annually.
- 3.Set the inflation assumptionEnter an annual inflation rate for withdrawals or hold withdrawals flat.
- 4.Review all rolling windowsCompare the success rate, failing start years, median and worst-case ending balances across every historical start year.
The tool embeds a fixed snapshot of annual S&P 500 total returns (including dividends) and 10-year US Treasury bond returns from the public NYU Stern / Damodaran table "Historical Returns on Stocks, Bonds and Bills", labeled with its update date in the interface.
No. Past sequences do not repeat on demand, valuation levels changed, and taxes, fees, and personal circumstances are excluded. A success rate describes historical windows only.
Only windows fully covered by data run at all. If your horizon is longer than the remaining years of the dataset, those start years cannot be backtested.
The simulation stops in the first year a requested withdrawal exceeds the balance after growth. That start year is reported as failing, and its remaining balance is zero.
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