The 4% rule: where it comes from and what breaks when you take it literally

The 4% rule says you can withdraw 4% of your wealth in the first year of retirement, increase that amount annually with inflation, and your portfolio will last thirty years.

Three things in that sentence are consistently misread: it's 4% of your starting capital rather than your balance, the rule was built for thirty years rather than forever, and 4% is a floor that had to survive the worst historical scenario, not an average.

What does the 4% rule actually say?

The full formulation, as intended:

1. Withdraw 4% of your portfolio in year one. On €1,000,000 that's €40,000.
2. Increase that amount each following year with inflation. At 3% inflation you withdraw €41,200 in year two, regardless of what your portfolio did.
3. Repeat for thirty years.

Point two is where it goes wrong. Most people think you withdraw 4% of your current balance annually. That's an entirely different strategy with an entirely different risk profile, and the difference is set out below.

Where the rule comes from

In 1994 the American financial adviser William Bengen published research walking through every possible starting year in American history, checking which withdrawal rate survived thirty years: including if you were unlucky enough to start just before a crash. His answer was roughly 4%, on a portfolio of around half to three-quarters equities.

In 1998 three professors at Trinity University repeated the exercise more broadly, across more portfolio compositions and horizons. That research, known since as the Trinity study, found success rates of roughly 95% for 4% over thirty years in American historical data.

From that 4% follows the rule of twenty-five times your annual spending, because 1 divided by 0.04 is 25.

Two things to hold on to. The research uses American equity and bond series from a century in which the US was the best-performing major stock market in the world. And it examines thirty years, which suits someone stopping at sixty-five and not someone stopping at fifty.

The three things most people get wrong

It's 4% of your starting capital

Under the rule as intended, your income is fixed in purchasing power. If your portfolio falls 30%, you still withdraw the same amount, and that's suddenly 5.7% of what's left. That's exactly where the risk sits.

Withdraw 4% of your current balance instead, and you can never go bust, because 4% of something is never all of it. But then your income moves with the market, and that can be brutal.

It was built for thirty years

For someone stopping at sixty-five, thirty years is reasonable. For someone stopping at fifty and living to ninety, it's forty. For someone stopping at forty-five, forty-five.

That difference isn't small. Look at the rate you can withdraw at a fixed real return without exhausting your capital:

At an infinite horizon the rate approaches your real return exactly: you live off the return and the capital stays.

It's a floor, not an average

Look at the table above: at a 4% real return over thirty years you could withdraw 5.78%. The rule says 4%.

That gap of nearly two percentage points isn't sloppiness. It's the price of uncertainty. The 4% isn't the answer at average returns: it's the answer that also survived if you happened to start in 1929 or 1966. Anyone withdrawing 4% in an average scenario dies with considerably more wealth than they started with.

What sequence risk is, and why it decides everything

This is the mechanism behind those two percentage points, and one example demonstrates it.

Take ten years of returns: three bad years (−20%, −10%, −5%) and seven years at +15%. Across those ten years that produces +81.9% in total, regardless of order.

Without withdrawals the order genuinely doesn't matter:

Exactly equal. Multiplication is commutative.

With withdrawals of €40,000 a year that changes completely:

€337,539 of difference, on precisely the same returns and precisely the same withdrawals. Only the order differs.

The reason is simple: withdrawing during a fall means selling a larger share of your holdings to reach the same amount. Those units are gone and don't participate in the recovery. The loss is made permanent by the withdrawal.

That's why the first ten years after you stop are the most dangerous period in your entire plan. A hit in year one weighs many times more than the same hit in year twenty.

Fixed amount or fixed percentage?

Back to the two readings of the rule, applied to that same bad sequence. Starting capital €1,000,000.

Two very different experiences.

With a fixed amount you keep your lifestyle but eat hard into capital during the bad years. After ten years you're €164,083 below the other approach.

With a fixed percentage your capital stays healthier, but your income drops to €26,542 in year three: a third less than you planned for. That isn't a theoretical inconvenience; that's whether you can still pay your rent.

Practice usually sits in between. Variants with a ceiling and a floor let your income move with the market while limiting how far it can fall in any year. That takes more attention than a rule of thumb and produces a sturdier plan.

What one percentage point does to your target

The withdrawal rate you choose directly determines how much wealth you need. At €40,000 of annual spending:

Moving from 4% to 3.5% costs you €142,857 of extra target: for many people several extra years of work. Moving from 4% to 4.5% saves the same, with more risk.

That's not an arithmetic choice but a risk choice, and it helps to name it as such rather than adopting a percentage because it appeared in a blog.

Does the 4% rule work in the Netherlands?

Partly, and differently from how it's usually assumed.

As a target calculation it doesn't work. Twenty-five times your spending assumes your wealth must carry your spending forever. In the Netherlands state and occupational pensions eventually arrive, so it doesn't. How that calculation does work is in the article on your FIRE number: for someone stopping at fifty with €40,000 of spending, the target is closer to €615,000 than to a million.

As a withdrawal rate it does work, with three caveats.

The rule is based on American historical data from the best-performing major equity market of the twentieth century. Research applying the same exercise to other countries arrives at lower safe rates: in some markets considerably lower.

The rule contains no wealth tax. In the Netherlands you pay annually on wealth above an exemption, which structurally reduces your net return. That belongs inside your real-return assumption.

And the rule covers thirty years. Anyone stopping at fifty should plan for forty.

So which rate then?

There's no figure that works for everyone, but there is a way to think about it.

Choose your rate based on your horizon, not on what's customary. The table earlier gives the ceiling at a fixed return; subtract something for sequence risk and you're in a defensible range.

Be more conservative in the bridge years. That's precisely the period when a hit does most damage, and the period when you have no state pension to fall back on. What you withdraw after your state pension date is a much smaller amount over a much shorter remaining horizon.

Keep flexibility in reserve. The difference between a plan that makes it and one that doesn't is often whether you can temporarily spend €4,000 less in a bad year. Anyone who can may take a higher rate. Anyone who can't should sit lower.

What this means for your bridge phase

The Dutch situation changes the question fundamentally, and in your favour.

In the bridge years you aren't making a perpetual withdrawal. You're making a planned drawdown with an end date. You know exactly how many years it must last and what arrives afterwards. That's an easier problem than the one the 4% rule solves.

Practically, that means you don't need to choose a rate for the bridge phase. You simply calculate what you need for that number of years, which is the annuity calculation from the FIRE number article.

The rate only matters after your state pension date, over the smaller remaining amount covering the gap, and then across a shorter remaining horizon, which supports a higher rate than 4%.

How Gylder fits in

The 4% rule is about withdrawing, and Gylder is a measuring instrument rather than a drawdown plan. What it does provide is the two figures every withdrawal strategy rests on.

Your actual wealth, continuously updated across all your accounts, so your withdrawal rate is calculated against a figure that's right rather than last year's estimate.

Your actual return, money-weighted with your deposits and withdrawals on their real dates. Once you start withdrawing, that's the only figure that still says anything: a time-weighted return tells you nothing about whether your plan holds.

And because your wealth is recorded daily, you see a bad sequence arriving as it starts rather than at your annual spreadsheet session.

What this doesn't tell you

The past is no promise. Every safe-withdrawal study looks backwards. A rate that survived every historical period may not survive the next.

The rule doesn't know your spending. It assumes a fixed amount moving with inflation. Actual spending fluctuates, and that fluctuation is usually your largest safety valve.

It doesn't know your life. Healthcare costs, a move, children studying, an inheritance. The rule carries on regardless.

And one thing that belongs in but falls outside this article: what you do in the year it goes wrong. A plan that only works if you never have to deviate isn't a plan.

Frequently asked questions

Is the 4% rule outdated? Not outdated, but often misapplied. As a withdrawal rate over thirty years in American data it's well supported. As a universal target for someone in the Netherlands stopping at fifty, it isn't.

Should I use 3.5% instead of 4%? At a horizon of forty years or more that's defensible. It does cost you over €140,000 of extra target at €40,000 of spending, so weigh it deliberately.

Do I take 4% of my balance or my starting amount? The rule as researched uses your starting amount, indexed annually. Taking it from your balance is a different strategy: you can't go bust, but your income swings considerably.

Does the rule apply to my bridge years? No, and that's favourable. For a period with a known end date you calculate an annuity, not a withdrawal rate.

Does the state pension count in the 4% calculation? Not in the rule itself, but very much in your situation. It lowers the amount that has to come from your portfolio, and therefore the wealth you need.