The 4% Rule for Retirement: How Much Can You Safely Withdraw?

June 30, 2026 · 6 min read

If you've read anything about retirement, you've met the 4% rule: the idea that you can withdraw 4% of your savings in your first year of retirement, adjust that amount for inflation each year after, and be reasonably confident the money lasts about 30 years. It's a handy benchmark — but it's widely misunderstood, and treating it as a guarantee can get you in trouble. Here's what it actually says and where it breaks down.

What the 4% rule says

Take your total retirement savings on day one and withdraw 4% of it that first year. Every year after, you give yourself a raise equal to inflation — you do not recalculate 4% of the new balance. The withdrawal is fixed in real (inflation-adjusted) dollars, regardless of what the market does.

A quick example

Say you retire with $1,000,000. The 4% rule says you withdraw $40,000 in year one. If inflation is 3%, you withdraw $41,200 in year two, and so on — even if your portfolio fell that year. The bet is that, across a 30-year retirement, a balanced portfolio earns enough on average to support those rising withdrawals without hitting zero.

Where it came from

The rule traces back to financial advisor William Bengen in 1994 and the "Trinity Study" that followed. They tested withdrawal rates against historical U.S. market returns and found that 4% survived every rolling 30-year period in their data for a stock/bond portfolio. That's a strong result — but notice the fine print: 30 years, historical U.S. returns, a specific portfolio mix.Change those and the "safe" number changes.

The 4% rule's blind spots

• Sequence-of-returns risk.A bad market in your first few years is far more dangerous than the same market later, because fixed withdrawals force you to sell more shares while they're cheap. Two retirees with the same average return can have very different outcomes depending on the order of those returns.
• Your time horizon may not be 30 years. Retire at 55 and you might need 40+ years — which lowers the safe rate. Retire at 70 and you may be able to spend more.
• Today isn't history. The rule rests on historical returns; periods of high valuations or low bond yields can make the future stingier than the past.
• Real spending isn't a flat line.Most people spend more early in retirement (the "go-go" years), less in the middle, then more again on healthcare late. A constant inflation-adjusted withdrawal doesn't match how anyone actually lives.
• It ignores your other income. Social Security and pensions can cover much of your spending, which often means you can safely withdraw a higher percentage from savings than 4%.

Better than a fixed rule: test your own plan

The 4% rule is a useful sanity check, not a spending plan. A better approach is to model your actual income, expenses, and accounts, then pressure-test the result two ways:

• Run a month-by-month projection to see whether — and when — the money runs out at the spending you have in mind.
• Run a Monte Carlo simulation (hundreds of randomized market paths) to see the probability your plan survives, not just one average-case line.

Many retirees discover their safe number isn't 4% at all — it's higher because guaranteed income covers a lot, or lower because they want a 40-year horizon. The only way to know is to model your own situation and adjust.

That's exactly what Retirement Forecast does: enter your numbers, set a withdrawal level, and instantly see both your projected run-out date and the odds your money lasts — then dial the spending up or down until you're comfortable.

This article is general education, not financial, investment, or tax advice. Projections are estimates that depend on your inputs and assumptions; consult a qualified professional about your own situation.