How Much Do You Need to Retire at 40, 45, or 50?

The target is two decisions, not one

Every "how much do I need to retire at X" answer is the product of two separate choices, and most disagreement about the answer is really disagreement about one of them.

1. 1What you plan to spend in a year. This is the larger term and the one you have most control over.
2. 2What multiple of that spending a retirement of that length requires — which is a question about withdrawal rates, not about you.

Target = Annual spending × Multiple

Multiple = 1 ÷ withdrawal rate

  4.00%  →  25×      3.33%  →  30×
  3.57%  →  28×      3.03%  →  33×

Why the multiple rises with a longer retirement

The 25× figure comes from the 4% rule, which was tested against a 30-year retirement. Someone stopping at 40 may need the portfolio to last fifty years or more, and the sustainable rate falls as the horizon extends — though with diminishing effect, flattening out in the low-3% range for horizons long enough to be effectively perpetual.

The gap between the top and bottom row is €320,000 — a large amount of additional work — and it comes entirely from a judgement about withdrawal rates rather than from anything about the retiree. This is why two people planning the same retirement at the same spending level can quote targets a third apart.

What each age implies about saving

Working backwards is more informative than working forwards. Starting from zero at 25, investing at a 5% return after inflation, these are the savings rates each target age implies:

Two things stand out. The first is how steeply the requirement falls with each five years of additional working life — from 53% to 34% between 40 and 50. The second is how little the multiple matters compared to the age: moving from 25× to 30× adds four percentage points to the savings rate, while retiring five years earlier adds ten or more.

What is different about retiring at 40 rather than 65

• Horizon. Fifty years of withdrawals rather than thirty, which is outside the range the original withdrawal research tested.
• No state pension for decades. A traditional retiree is often bridging a few years to a pension; an early retiree is funding the entire gap from the portfolio, though the pension arriving later does reduce what the portfolio must cover indefinitely.
• Access restrictions. In many countries a substantial share of retirement savings sits in accounts that cannot be drawn on until a set age, so the portfolio that matters is the accessible one rather than the total.
• Healthcare and insurance. Arrangements tied to employment end, and the cost of replacing them varies enormously by country.
• Sequence risk over a longer window. More years of withdrawals means more opportunities to encounter a bad sequence early in the drawdown.
• More scope to adapt. A 40-year-old retiree has decades of potential earning capacity remaining, which is a genuine buffer that a 70-year-old does not have.

What the arithmetic assumes

• A constant 5% return after inflation for the whole accumulation period, with no sequence effects.
• A constant savings rate throughout, with no career breaks, no children, and no periods out of work.
• Starting from zero at 25. Existing savings reduce every figure in the table, often substantially.
• Spending in retirement equal to spending now, which for most people is neither obviously right nor obviously wrong.
• No state pension, inheritance, or property sale. Any of those arriving later reduces what the portfolio must carry.
• That the chosen multiple is adequate — which inherits every limitation of the withdrawal-rate research it comes from.