The Horizon Half of Australian Couples Should Plan To
Life expectancy is an average, and half the people it describes live longer. For a couple the number that matters is not either partner's expectancy but the age at which the second of them dies, which is materially later — and planning to an average leaves a large minority of households outliving their money at exactly the age they can do least about it.
- The answer: Use life expectancy conditional on having reached 65, not at birth, and for a couple use the joint expectation of the second death.
- The trap: Planning to the average means half of comparable households outlive the plan. The distribution matters more than its centre.
- The recommendation: Test the plan at 95 and at 100. The Age Pension is the floor that makes those scenarios survivable rather than catastrophic.
Where the AI summary above gets this wrong
"Australian life expectancy is about 83 for men and 86 for women, so plan for a 20-year retirement."
That's surface-true. Here's what it misses:
- Those are figures at birth, not at 65 — Someone who has already reached 65 has survived the mortality of the earlier decades, and their expectancy is several years higher than the at-birth figure.
- An average leaves half of households beyond it — Planning to the centre of a distribution is planning for a coin-flip. The relevant question is how bad the outcome is in the upper tail, not where the middle sits.
- For a couple the horizon is the second death — The probability that at least one of two people is still alive is considerably higher at every age than the probability for either individually.
01 Which number to use
Life expectancy at birth includes the mortality of every earlier decade. Someone who has reached 65 has already survived all of that, so their remaining expectancy is longer than the at-birth figure suggests. The ABS publishes both, and the conditional figure is the one a retirement plan needs.
For a couple, the horizon is the second death rather than the first. At every age, the chance that at least one of two people is alive is higher than the chance for either, and the gap widens into the nineties.
That makes a couple's planning horizon several years beyond either partner's individual expectancy, and it is the reason single-life expectancy figures systematically understate how long a household's money has to last.
02 Why the tail matters more than the average
A plan that funds an average lifespan fails for half of the households it describes. That would be unacceptable for any other risk, and it is accepted here because the failure is decades away and invisible at the point the plan is made.
The cost of planning longer is modest, because the extra years are at the end when spending is lower and the sustainable withdrawal rate has largely flattened. The cost of planning too short is borne at 92 by someone with no capacity to earn.
That asymmetry is the whole argument. It is not that living to 100 is likely; it is that the consequence of being wrong in one direction is far worse than in the other, and covering it is cheap.
Shows: the additional capital needed to fund the gap between your spending and the Age Pension for extra years beyond your planning age. Ignores: the fall in spending in later years, the rise in care costs, inflation, and the increase in Age Pension as assets fall.
03 What makes the long tail survivable
The Age Pension is the structural answer. It is indexed, it is paid for life, and it rises as assets fall — so a household that exhausts its portfolio at 94 does not have nothing, which is the difference between an Australian long-life scenario and the one the international research describes.
A lifetime income stream is the purchasable version of the same protection, with the means-test concession described in the annuity post making it cheaper than it first appears for a part-pensioner.
And flexibility is the behavioural version. A household able to reduce discretionary spending in response to a long life or a bad sequence survives scenarios that break a household committed to a fixed real amount.
Source: Services Australia — How much Age Pension you can get
Planning to the average is planning to be wrong half the time, and the half you get wrong is the expensive one. The extra years are cheap to cover — spending is lower by then and the pension is doing more of the work — which makes this one of the few risks in a retirement plan you can largely remove for very little.
FAQ
How do I check whether my plan still works if I live to 100?
Run the projection to 95 and to 100 and see whether the conclusion changes. The extra years are cheaper than they look because spending is lower late and the sustainable withdrawal rate flattens out.
What life expectancy should I use for planning?
The expectancy conditional on having already reached 65, not the at-birth figure, and for a couple the joint expectation of the second death rather than either individual's.
How do I plan for the chance that one of us lives much longer than the other?
Plan to the second death. At every age the chance that at least one of two people is alive is higher than for either individually, and the gap widens into the nineties.
Sources
Regulator references
- Australian Bureau of Statistics — Life expectancy · Australian Bureau of Statistics · 2026The ABS life expectancy series, used for the planning horizon.Last verified: 2026-09-07
- Services Australia — How much Age Pension you can get · Services Australia · 2026The current payment rates, and the March and September indexation that moves them.Last verified: 2026-09-07
Calculator unit tests · the assertions this page's worked example is checked against, and their last result
Changelog
- 2026-09-07 — initial publish (new format)
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Jordan Reeves
Founder of Talk Through Wealth. A software engineer for over a decade before turning to retirement planning, Jordan built the projection engine after watching family members get fragmented, country-by-country advice that never reconciled. He writes about retirement the way the engine computes it: month-by-month, lifetime-long, and skeptical of any rule of thumb that hasn't been run through the math.