The 12% rule – why it's controversial (and how it stacks up against the 4% rule)

The 12% rule was popularised by American personal-finance personality Dave Ramsey and rests on two claims: that "good stock mutual funds" have historically returned about 12% per year, and that you can therefore safely withdraw around 8% of your portfolio every year in retirement. It sounds generous – and that is exactly why it has become so widely quoted and so heavily criticised.

The number comes from the long-term arithmetic mean of S&P 500 annual returns, which does land somewhere around 11–12% nominal. The problem is that the arithmetic mean is not the same as the return your portfolio actually grows by over time. The geometric return (CAGR) – the one compounding actually uses – has historically been closer to 10% nominal and only about 6.5–7% in real terms, i.e. after inflation.

The difference is not academic. A year of +20% followed by a year of –20% gives an arithmetic mean of 0%, but your portfolio is actually down 4%. The more the market swings, the bigger the gap between the optimistic average and real growth. Planning with 12% in a FIRE projection therefore overstates both your end capital and how much you can withdraw.

Beyond that, the rule ignores things that matter a lot in practice: inflation eating into purchasing power, taxes (such as Sweden's ISK schablon), fund fees, and – not least – sequence-of-returns risk: the risk that the market drops sharply right when you start withdrawing, which can drain a portfolio far faster than any average suggests.

This is where the 4% rule from the Trinity study shines. It tested actual 30-year periods and found that an inflation-adjusted withdrawal of roughly 4% per year survived in about 95% of cases. Withdrawing 8% instead – as the 12% rule implies – failed in the majority of periods, often because the portfolio ran out long before 30 years had passed.

Practical takeaway: plan your base case with roughly 7% real return and a 3.5–4% withdrawal rate. Feel free to use 10–12% as an optimistic side scenario to see what happens if markets are unusually kind – but never make it the basis for when you hand in your notice.

Try it yourself in the calculator below: first set return to 12% and withdrawal to 8%, then switch to 7% and 4%. Compare years to FIRE and sustainable monthly withdrawal. The gap between those two scenarios is the whole reason the 12% rule is so controversial.