What is Safe withdrawal rate?

A safe withdrawal rate is the percentage of a retirement portfolio that someone takes out in the first year, then raises each year in line with inflation (the general rise in prices), without the money running out over a chosen period, usually 30 years. The word safe means the rate survived the bad stretches in the historical record. It does not mean risk-free. The best-known version is the 4% rule, associated with William Bengen.

Say you retire with $1,000,000 and use a 4% rate. In year one you withdraw $1,000,000 × 4% = $40,000. If prices rise 3% that year, the year-two withdrawal is $40,000 × 1.03 = $41,200. Another 3% rise gives $41,200 × 1.03 = $42,436 in year three. The amount follows prices, not the market. Now suppose the portfolio falls 20% early on. After the first $40,000 is taken, $960,000 remains. A 20% fall leaves $768,000, and the next $41,200 is about 5.4% of what is left ($41,200 ÷ $768,000). This is why the rate refers to the starting balance, not the current one.

History gives a sense of how the rule has held up. For a 60/40 portfolio (60% US stocks, 40% bonds), US data from 1872 to 2025 shows that a 4% withdrawal rate lasted through 30-year retirements in 124 of 125 start years. The one failure started in 1966. Still, the figure describes the past and is not a forecast. Results depend on sequence of returns risk, meaning the danger that heavy losses arrive early, while withdrawals are eating into a shrunken balance. Fees, taxes, a different mix of assets or a retirement longer than 30 years all change the answer. A common misunderstanding is that the rule means taking 4% of whatever the portfolio is worth each year. That is a different method, and its income rises and falls with markets.

For a private investor building a long-term portfolio, the safe withdrawal rate turns a vague goal into a number. Dividing the yearly spending needed by the rate gives a rough target. For example, $40,000 a year at 4% points to $1,000,000. It also shows why the order of returns and the spread between stocks and bonds matter as much as the average return. Many investors treat the rate as a starting point and adjust their spending when markets are unusually strong or weak.

By Dr. Harry Hamann

What is the 4% rule?
The 4% rule says a retiree withdraws 4% of the portfolio in the first year, then adjusts that dollar amount for inflation each year. In US data from 1872 to 2025, a 60/40 portfolio lasted 30 years in 124 of 125 start years.

Does the safe withdrawal rate always work?
No. It is based on historical market returns, and the future may differ. Higher fees, a longer retirement, or a run of poor returns early in retirement can cause a rate that worked in the past to fall short.

Does the safe withdrawal rate include inflation?
Yes, in the classic version. The first-year amount is set as a percentage of the starting portfolio. After that the dollar amount rises with inflation, so spending power stays roughly constant whatever markets do.

How does retirement length affect the withdrawal rate?
Most studies assume a 30-year retirement. A longer period means the money must last more years and survive more bad markets, so historical studies generally find lower sustainable rates for longer retirements.