The 4% Rule (Safe Withdrawal Rate), Simply Explained

The 4% rule, also called a safe withdrawal rate, is a rough guideline for how much you can withdraw from a retirement portfolio each year without a high risk of running out of money. The idea: in your first year of retirement, withdraw about 4% of your total portfolio's value, then adjust that dollar amount for inflation each year after, roughly keeping your spending power steady over a long retirement.

It comes from looking back at long historical stretches of market returns and asking: if someone had retired at the start of nearly any of those stretches and withdrawn 4% in year one, adjusting for inflation every year after, how often would their portfolio have lasted roughly 30 years without hitting zero? The answer, across most historical periods studied, was: most of the time.

A quick worked example makes it concrete: a portfolio worth $1,000,000 following the 4% rule would support a first-year withdrawal of $40,000, then that $40,000 would be adjusted upward each following year to keep pace with inflation.

Portfolio value:  $1,000,000
Withdrawal rate:  4%

Year 1 withdrawal:  $1,000,000 x 0.04  =  $40,000
Year 2 and beyond:  $40,000, adjusted upward each year for inflation

The 4% rule suggests withdrawing about ____ % of a portfolio's starting value in year one of retirement, then adjusting that amount for inflation each year after.

In the 4% rule, how is the withdrawal amount typically handled after the first year?

A safe withdrawal rate like this turns a vague goal ('save a lot') into a specific, checkable target: a portfolio size that, combined with a reasonable withdrawal rate, could realistically cover your expenses for decades without needing to earn a paycheck.

The 4% rule is based on looking back at long historical periods of market returns, not a mathematical guarantee about the future.