What is a safe withdrawal rate?
A safe withdrawal rate is the share of your starting portfolio you can take out in your first year of retirement, then adjust for inflation each year after, with a high chance the money lasts your whole retirement.
The key word is rate. It is a percent of your starting balance, not a fixed dollar figure, and it is set once at the start. A 4% rate on a $1,000,000 portfolio means $40,000 in year one, then that same $40,000 grown by inflation each year after, regardless of what the portfolio does next.
The 4 percent rule was never 4 percent
In 1994, financial planner William Bengen tested withdrawal rates against decades of historical US market returns. The highest starting rate that survived every rolling 30-year period was about 4.15%, a figure he named the SAFEMAX. The 1998 Trinity Study reinforced the idea, and somewhere along the way the number got rounded down and frozen in the public mind as a flat 4%.
The story did not stop there. In his 2025 work, Bengen revisited the question using broader diversification across seven asset classes and raised his own safe starting figure to about 4.7%. And studies of how retirees actually spend find real-world withdrawals often land closer to 2%, because spending tends to drift down in real terms as people age. So the honest picture is a range: the famous rule understates what the math supports, and overstates what most retirees actually take.
The full history, with each figure traced to the original papers, is covered in a companion article, The 4% Rule Was Never 4%.
The short version: most people are told 4%. The original research said 4.15%. Bengen's own update says 4.7%. Real retirees often take closer to 2%. The single number you have heard your whole life is the least useful part of the story.
How to calculate your withdrawal rate
- Add up the portfolio you will actually draw from in retirement.
- Decide how much you plan to withdraw from it in your first year.
- Divide the first-year withdrawal by the portfolio value, then multiply by 100.
- Compare the result to the range above: under 4.15% is conservative, 4.15% to 4.7% is moderate, and higher than that needs spending rules to stay safe.
A worked example
Take a $1,000,000 portfolio and three different first-year spending plans. The rate, not the dollar amount, is what tells you how much risk you are taking.
| First-year spending | Portfolio | Withdrawal rate |
|---|---|---|
| $35,000 | $1,000,000 | 3.50% |
| $40,000 | $1,000,000 | 4.00% |
| $55,000 | $1,000,000 | 5.50% |
The $40,000 plan is the famous 4%, and it sits just under Bengen's real 4.15% starting point. The $55,000 plan at 5.50% is above every classic static guideline, sustainable only with the kind of spending rules covered below. The calculator above starts on the $40,000 case so you can move either number and watch the rate cross the benchmarks.
Static rate vs dynamic guardrails
The 4% rule is a static strategy: set the rate once, then spend the same inflation-adjusted dollars every year no matter what the market does. It is simple, and that simplicity is also its weakness, because it ignores the portfolio in front of you.
Guardrail strategies fix that. Jonathan Guyton and William Klinger showed that if you let spending flex with the portfolio using a few decision rules, you can start at a higher rate and still protect the plan. Two rules do most of the work:
Capital preservation rule. If your current withdrawal rate climbs more than 20% above your starting rate, usually because the portfolio has fallen, you cut that year's spending by 10% to let it recover.
Prosperity rule. The mirror image. If the portfolio runs well ahead and your current rate drops well below the start, you give yourself a raise. Permission to spend more, earned by the math.
With rules like these and a high allocation to stocks, the research supports starting rates above the static 4%, because spending bends in bad years instead of draining a shrinking portfolio at a fixed dollar amount. The tradeoff is that your income is no longer perfectly flat. You accept some variability in exchange for a higher average and a sturdier plan.
Why your safe rate is personal
Any single published rate is an average across history. Yours depends on details a flat number cannot see.
How long the money has to last
The original 4.15% was built on a 30-year retirement. Retire at 56 and you may be planning for 40 years, which pulls the safe starting rate down. Retire at 70 and a shorter horizon supports a higher one.
Sequence of returns
The order in which gains and losses arrive matters enormously once you are drawing the portfolio down. A bad first decade does far more damage than the same bad decade later, even when the long-run average return is identical. This is the single biggest reason a fixed-dollar rule can fail.
How much sits in stocks
The higher safe rates in the research lean on equity-heavy portfolios, often 65% or more in stocks. A conservative allocation is steadier year to year but tends to support a lower sustainable withdrawal rate, not a higher one.
Common mistakes
Treating 4 percent as a fixed law
It was one planner's historical finding, rounded off, for one set of assumptions. The real research has already moved the number in both directions.
Counting outside income in the rate
Your withdrawal rate is the draw on the portfolio only. Social Security and pensions reduce how much the portfolio has to cover, which is exactly why they lower the rate you actually need.
Setting the rate once and never looking again
A static rate ignores the portfolio in front of you. The guardrail approach, checking your current rate against where it started and adjusting, is what turns a one-time guess into a plan that responds to reality.
Keep going from here
Questions people ask
What is a safe withdrawal rate?
It is the percent of your starting portfolio you can take in year one, then adjust for inflation each year after, with a high chance the money lasts your full retirement. It is a percent of the starting balance, not a fixed dollar amount.
Is the 4 percent rule actually 4 percent?
No. Bengen's original 1994 research found about 4.15%, the figure he called the SAFEMAX. It was rounded down to a flat 4%. In 2025 he revisited it with broader diversification and raised his own safe starting figure to about 4.7%.
Can I withdraw more than 4 percent?
Sometimes. Dynamic guardrail strategies, like the Guyton-Klinger rules, let spending flex with the portfolio and have supported higher starting rates, but only with rules that cut spending in bad markets and a high stock allocation. A higher static rate with no adjustments raises the risk of running out.
How do I calculate my withdrawal rate?
Divide your planned first-year withdrawal from the portfolio by your total portfolio value, then multiply by 100. For example, $40,000 drawn from a $1,000,000 portfolio is a 4.0% rate.
Does this calculator store my numbers?
No. Everything runs in your browser. Nothing you type is sent to a server or tied to an account.
From a rate to a plan that holds up
A withdrawal rate is one input. Plan With Clarity takes it into a full retirement projection: a withdrawal strategy with guardrails, taxes, Social Security timing, healthcare costs, and a Monte Carlo stress test that runs your plan across thousands of different return orderings, the sequence-of-returns risk a single rate cannot show.
Open Plan With ClarityNo account linking and no selling of your data. You can run the core models without connecting any outside financial accounts.