The 4% Rule Calculator

The 4% rule says you can withdraw 4% of your portfolio in your first year of retirement, then raise that dollar amount by inflation every year, and the money should last at least 30 years. It comes from William Bengen's 1994 research and the later Trinity study, which tested withdrawals against historical U.S. market returns. This calculator replays the rule for every start year since 1926.

Multiply your annual spending by 25, which is the same as dividing it by 4%. For example, spending $80,000 a year means you need $2,000,000. Choose "I know my spending" in the calculator above to run your own number through every historical start year.

Historically it mostly held up: a 4% withdrawal from an all-stock portfolio lasted 30 years in 67 of 71 start years since 1926 (94.4%). Past returns don't guarantee future ones, though, and the rule was designed for 30-year retirements. A lower withdrawal rate or a willingness to cut spending in bad years adds a margin of safety, especially for early retirees.

Lower rates have been safer: over 30 years, 3.5% succeeded in 100% of start years and 3% in 100%, versus 94.4% at 4%. The trade-off is a bigger portfolio, about 28.6x your annual spending at 3.5% and 33.3x at 3%, instead of 25x. Try 3.5% or 3% in the calculator.

With a 4% withdrawal, 4 of 71 start years failed the 30-year test: 1929, 1966, 1968, and 1969. Each year's page shows how the portfolio and withdrawals evolved until the money ran out. Retirements starting in 1930, 1965, 1967, and 1973 also ran out eventually, but only after more than 30 years.

Yes. Each year's withdrawal is the previous year's amount raised by that year's CPI inflation, so your spending power stays the same. For example, a $40,000 first-year withdrawal becomes $41,200 after a year of 3% inflation. Portfolio balances on this site are in nominal dollars, not adjusted to today's money.

The main backtest assumes the whole portfolio is in the S&P 500 with dividends reinvested. Next to it, the calculator shows the Trinity study's stock/bond mixes (75/25, 50/50, 25/75 and all bonds), using 10-year U.S. Treasuries rebalanced every year. It ignores fees, taxes, and income such as Social Security or a pension. Fees and taxes would make results worse, while Social Security lowers how much your portfolio has to cover, so you can subtract expected benefits from your spending before using the calculator. See the methodology for every assumption.

S&P 500 total returns and CPI inflation come from Robert Shiller's dataset at Yale University. The calculator uses January-to-January annual returns from 1926 through 2025, and tests every start year with at least 10 years of data. The methodology page explains exactly how each year is calculated.