Ninety summers,
if you're lucky

The whole life, on one screen

A life of eighty years is about four thousand weeks. That count is Oliver Burkeman’s, and drawing a life as a grid of squares is Tim Urban’s. Both are right. Both also assume the number is fixed, which is where this page goes somewhere else.

Start where they start. Weeks are too many to picture. Summers you can hold in your head, because you remember them.

Ninety squares. Australian life expectancy is about 81 for men and 85 for women¹; the last decade is drawn lighter because it is a hope rather than a plan.

The sub-counts are what hurt

The total is generous enough to feel abstract. The smaller counts are not. Urban ran this arithmetic on himself and found he had spent about ninety-three per cent of his in-person time with his parents by the time he left home at eighteen.² The rest of a lifetime together was already behind him at eighteen, and nobody announced it. Almost every relationship has its own clock running faster than yours, and it usually runs out quietly, without a final occasion to mark it.

Summers with your kids at home

Children run the same arithmetic from the other end. If they leave home at eighteen, you get eighteen summers under one roof, and the early ones go fastest because you're too busy to count them. Many don't leave at eighteen any more, so set that too.

The week you actually get

Everyone has 168 hours. The question is never where the week went, because the week goes to the same places every time. It is which squares you are willing to move.

Thirty-two discretionary hours a week on this illustrative split, and most of them get spent by default rather than by choice. That is not a moral failure, it is a default. Defaults are chosen by whoever built them, and none of them were built by you.

Where your day actually goes

Set an average day. Not your best day, and not the one you would describe to a stranger. The average, including the evenings that dissolved. The page will do the multiplication you have been avoiding.

An hour a day is fifteen days a year. Fifteen and a half days you spend awake, doing one thing, whether or not you chose it. Three hours a day is a month and a half. Over a remaining forty years, three hours a day is five straight years of your life, and the only question that matters is whether the thing is worth five years.

The same hours, by stage

Time is not uniform. An hour at thirty-two, with small children asleep down the hall, does not buy what an hour at seventy-two buys. The grid is flat; the life is not. So the useful question is not how many years remain, but how many of each kind.

Stage boundaries are conventions, not biology, and the last one is the one people plan for hardest and get least reliably. On AIHW figures, Australian men spend on average 9.7 years of their lives in ill health and women 11.5 years.¹ That gap is where the difference between years and good years lives.

The 120-year plan

One hundred and twenty is not fantasy, it is the edge of the observed record. Jeanne Calment reached 122 and died in 1997, and nobody since has got near her.³ So the 120-year plan is not a bet on new biology. It is a bet that you land in the extreme tail of the distribution that already exists, where so far exactly one verified person in history has been. That is why it only becomes a real plan if ageing itself becomes treatable.

Switch the grid above to 120 and the shape of the problem changes more than the size. The three-stage life — learn, earn, retire — is an artefact of a forty-year career funding a twenty-year retirement. Stretch the end and the arithmetic breaks in four places.

• The career becomes careers. Employers surveyed by the World Economic Forum expect 39% of workers' core skills to change by 2030 alone.⁴ Stretch that across a ninety-year working life and you are relearning many times over, not climbing one long ladder. Every stage needs a deliberate re-entry into being a beginner, which is the single hardest thing for people who are respected at what they currently do.
• Savings stop working the way you were taught. Forty years of contributions cannot fund sixty years of drawdown. The 120-year plan is funded by earning across the whole span, not by accumulating and then stopping.
• Your cohort dies before you do. This is the cruelty nobody plans for. Longevity without intergenerational friendship is solitary confinement with good bloodwork. Making new, younger friends is a longevity practice, not a social nicety.
• Healthspan is the binding constraint, not lifespan. Australians currently spend around ten to eleven of their years in ill health.¹ Extra years arrive at the end, in the worst stage, unless healthspan moves with them. Twenty extra years of frailty is not a gift.

There is a third span most people never plan: the working one. A career designed for an eighty-year life doesn't stretch to a hundred and twenty on its own.

Why the long plan stopped being science fiction

For most of history the only strategy against ageing was to manage the decline. That is changing, and you can see it in regulators' decisions, not just press releases.

• Old cells, made younger, in a person. In 2026 the FDA cleared the first human trial of partial epigenetic reprogramming, and the first patient was dosed in June. It starts in the eye, and so far it only has to prove it's safe.
• Lost brain cells, replaced. In March 2026 Japan gave conditional approval to the first therapies made from reprogrammed stem cells, one for Parkinson's and one for heart failure.
• Insulin cells grown in a lab. Ten of twelve people with type 1 diabetes no longer needed insulin a year after a stem-cell islet infusion.
• Organs from a new supply. The first formal clinical trial of gene-edited pig kidneys began in late 2025.
• China is moving in parallel. A Peking University team reversed one woman's type 1 diabetes with islets grown from her own fat cells, Chinese Academy of Sciences researchers made aged monkeys measurably younger, and surgeons in Hefei put the first pig liver into a living patient.
• Ageing itself, as a drug target. The FDA has accepted the effectiveness and safety sections for a drug meant to extend the lifespan of senior dogs. If it clears the last step, it will be the first approved lifespan drug in any species.

None of this proves anyone will live to 120. No intervention has yet extended maximum human lifespan. What it shows is a shift from slowing damage to repairing and replacing it, and that shift is what the long plan depends on.

The 150-year plan

Here the honesty has to be sharper. No human has lived past 122. Analyses of how the body loses its ability to bounce back from stress put an absolute ceiling somewhere between 120 and 150³ — a point where resilience reaches zero regardless of disease. Reaching 150 would require reversing accumulated damage, not slowing it. Nothing available today does that in a human.

So treat 150 as an option, not a plan. Options have a premium, and the premium is what you do differently now on the chance the payoff exists.

• Do not burn the body for money you will have time to earn anyway. The trade that made sense over a forty-year career — sleep, health, and relationships sold for advancement — is catastrophic over a hundred-year one. You would be spending the scarce asset to buy more of the abundant one.
• Prefer compounding to consumption. Not only money. Health, reputation, skill, and relationships all compound, and compounding is the only thing that gets qualitatively better with a longer horizon.
• Stay adjacent to the frontier. The version of you who benefits from anything real is the version who was still paying attention, still solvent, and still healthy enough to qualify.
• Protect optionality over certainty. Anything that locks you into one identity for eighty years is a larger bet than it looks.

Note what happens if the bet loses. Every item on that list is also the correct plan for eighty years. That asymmetry is the whole argument. You are not sacrificing the shorter life to chase the longer one.

Ikigai, and what fills the extra years

Extending life raises a question that a forty-year career answers by accident and a hundred-year one cannot: what are you getting up for, on an ordinary Tuesday, in year ninety-four?

Iki is life. Gai is worth. In Okinawa, where the word is lived rather than diagrammed, ikigai is small and daily. The garden. The grandchild. The neighbour you check on. It is the reason to rise in the morning, and it is the one thing on the longevity list that does not need a laboratory.

The diagram you have seen a thousand times. It is worth knowing it is not Japanese: it is a 2014 mashup of a Spanish purpose chart with a word borrowed from a Blue Zones talk.⁵

The distinction matters over a long life. The Venn version is achievement-shaped, and achievements run out. Mornings do not. A purpose that depends on being paid, being the best, or being needed by the market will expire somewhere in your second act and leave forty years unaccounted for. A purpose that renews daily will not.

In a study of nearly 7,000 Americans over fifty, those with the weakest sense of purpose were about 2.4 times as likely to die over the following years as those with the strongest.⁶ It is an association, not proof: illness can erode purpose as easily as purpose protects health. But of everything currently on offer in the longevity market, a reason to get up tomorrow is the cheapest, the best evidenced, and the only one that also improves the years you were always going to get.

How to choose

Time management assumes the problem is throughput. It is not. You will not get to the bottom of the list, because finishing work creates more work. The only real decision is what you are willing to leave undone on purpose.

1. Pay yourself first. The thing that matters most gets the first hour of the day, not the last one, which never comes. Whatever is left over goes to the residual claimants: email, other people's urgency, the algorithm.
2. Decide what you are consciously failing at. Not everything can be first. Naming the three things you are deliberately doing badly this year is what makes the other three possible.
3. Count the occasions, not the years. If someone matters, work out how many times you will realistically see them again. Then decide whether four a year is the number you actually meant.
4. Prefer the reversible fast, the irreversible slow. Most decisions are doors that swing both ways, and agonising over them is itself the cost. A few are one-way. Spend the deliberation there.
5. Watch where the hours leak, not where they are spent. Nobody decides to lose an evening. It goes in ten-minute pieces to things that were designed to take them.
6. Protect attention before you protect time. An unbroken hour and an hour cut into six pieces are the same square on the grid and not remotely the same hour.

The one rule

Almost every regret people report at the end is symmetrical. Not that they worked too little, but that they worked while the people they loved were still available to them. Not that they did too few things, but that they spent so much of the grid waiting for a version of life that was going to begin later.

Go back to the top and set the slider to your own age. Then take the sub-count you are least game to calculate, and calculate it. That is the one that changes what you do next week.

Further reading

The books and essays this page stands on, and a few that argue with it.

Sources

1. Australian Institute of Health and Welfare, Australia's health 2024: life expectancy 81.2 (men) and 85.3 (women) for 2020–22, and 9.7 and 11.5 years spent in ill health. Reported by RACGP newsGP; see also ABS, Measuring What Matters.
2. Tim Urban, The Tail End, Wait But Why.
3. Pyrkov et al., Longitudinal analysis of blood markers reveals progressive loss of resilience and predicts human lifespan limit, Nature Communications, 2021; summarised by Scientific American, which also notes Jeanne Calment's record of 122.
4. World Economic Forum, Future of Jobs Report 2025, skills outlook.
5. Ikigai Tribe, Ikigai FAQ, on Andrés Zuzunaga's purpose diagram and Marc Winn's 2014 relabelling.
6. Alimujiang et al., Association Between Life Purpose and Mortality Among US Adults Older Than 50 Years, JAMA Network Open, 2019.

The 168-hour week and the day calculator use illustrative figures, not survey data. Last updated September 2026.