Your life in weeks, explained
An 80-year life is about 4,160 weeks. At US life expectancy at birth from the SSA 2023 period life table, that is about 3,940 weeks for a man (75.8 years) and 4,215 weeks for a woman (81.1 years). This calendar draws each of those weeks as one square: 52 squares per row, one row per year. To find how many weeks you have lived, multiply your age by 52.
Life tables: US Social Security Administration, period life table 2023. The grid idea: Tim Urban, Wait But Why, 2014.
How to calculate your life in weeks
Enter your age and the life expectancy you want to use. The calendar then works out:
- Weeks lived = your age × 52.
- Total weeks = your life expectancy × 52.
- Weeks ahead = total weeks − weeks lived.
For example, at 30 with a life expectancy of 80, you have lived 1,560 weeks out of 4,160, and about 2,600 are ahead. That is 38% of the grid. A calendar year has slightly more than 52 weeks (52.18), so these are round figures.
The default of 80 years is only a starting point. For a number based on your own age, sex, country and habits, use the life expectancy calculator and enter that result here.
How many weeks are left at my age?
These are the average weeks remaining at each age in the United States, from the SSA 2023 period life table (remaining life expectancy × 52). Your own number depends on your health, habits and country.
| Age | Men: years left | Men: weeks left | Women: years left | Women: weeks left |
|---|---|---|---|---|
| 0 (birth) | 75.8 | 3,941 | 81.1 | 4,215 |
| 20 | 56.7 | 2,948 | 61.7 | 3,210 |
| 30 | 47.5 | 2,470 | 52.1 | 2,708 |
| 40 | 38.6 | 2,007 | 42.6 | 2,217 |
| 50 | 29.9 | 1,555 | 33.5 | 1,739 |
| 60 | 21.8 | 1,133 | 24.7 | 1,286 |
| 70 | 14.7 | 762 | 16.8 | 872 |
| 80 | 8.5 | 442 | 9.8 | 511 |
| 90 | 4.1 | 214 | 4.8 | 250 |
Remaining life expectancy does not fall by a full year for each year you live. The older you get, the further your expected age at death moves out, because you have already survived the years before. For the full table by single year of age, see life expectancy by age.
Why look at your life in weeks?
Years feel abstract. Weeks are a unit you live through every day, so seeing them all on one page makes time easier to picture. Tim Urban’s 2014 essay “Your Life in Weeks” made the grid popular, and Oliver Burkeman’s book Four Thousand Weeks (2021) takes its title from the length of an average life.
People use the calendar in different ways:
- As a memento mori, the old Stoic reminder that time is limited, to help decide what matters.
- To plan in chunks, for example the weeks until a child leaves home or until retirement.
- To see what is still ahead. Even at 60, a US woman has about 1,286 weeks on average, which is a lot of Saturdays.
If seeing the numbers feels heavy, that is normal. The point of the grid is the empty squares, not the filled ones.
Life in weeks FAQ
How many weeks are in a human life?
About 4,160 weeks in an 80-year life. At US life expectancy at birth (SSA 2023), it is about 3,940 weeks for men and 4,215 weeks for women.
How do I calculate how many weeks I have lived?
Multiply your age in years by 52. A 40-year-old has lived about 2,080 weeks. For an exact count, divide the days since your birth by 7.
How many weeks do I have left?
Subtract the weeks you have lived from your life expectancy × 52. On average, a 40-year-old US man has about 2,007 weeks left and a 40-year-old woman about 2,217.
What is a life calendar?
A life calendar is a grid with one square for every week of a long life, usually 52 squares per row and 80 to 90 rows. You fill in the weeks you have lived to see your whole life at a glance.
Who came up with the life in weeks idea?
The popular version comes from Tim Urban’s 2014 Wait But Why post “Your Life in Weeks”. The idea of counting your remaining time is much older, from the Stoic practice of memento mori.
Last reviewed: · Sources · For reflection, not medical advice.
Sources
- US Social Security Administration. Actuarial Life Table: period life table, 2023 (2026 Trustees Report).
- Urban T. Your Life in Weeks. Wait But Why, 2014.
- Burkeman O. Four Thousand Weeks: Time Management for Mortals. Farrar, Straus and Giroux, 2021.