About this tool
Life in Weeks draws one small square for every week of a life: 52 squares per row, one row per year of life expectancy, so an 80-year life is a grid of 4,160 squares. Weeks you have already lived are filled in, the current week is highlighted, and the rest are left empty. Alongside the grid it reports weeks lived, weeks remaining, the percentage of the expected span used, days lived, and the dates of your next 1,000-week, 10,000-day, and 20,000-day milestones. It is a reflection tool in the spirit of the well-known Wait But Why chart, useful for anyone who wants an honest, visual sense of how much time a life contains.
How it works
Dates are parsed as local calendar dates at midnight, so days lived is the whole number of days from your birth date to today, computed as Math.round((today - birth) / 86,400,000) to stay correct across daylight-saving changes. Weeks lived is days lived divided by 7, rounded down. The grid treats a year as exactly 52 weeks (364 days), so total squares = expectancy x 52; the 1.25 leftover days per year are ignored in the grid but the calendar life-expectancy date shown in the stats is exact. Milestone dates are birth date plus 7,000 days per 1,000 weeks, plus 10,000 days, and plus 20,000 days.
Frequently asked questions
How many weeks are in an 80-year life?
Roughly 4,174 weeks by the calendar (80 years is 29,220 days, and 29,220 / 7 = 4,174.3). The grid rounds each year to 52 weeks, which gives 4,160 squares. Either way, a long human life is only about four thousand weeks.
Why does the grid use 52 weeks per year instead of 52.18?
A grid needs whole rows. Treating every year as 52 weeks makes each row line up with a birthday, at the cost of drifting about 1.25 days per year. Over 80 years that is about 100 days, or 14 squares, which we show in the stats rather than hide.
Where does the default life expectancy of 80 come from?
It is close to period life expectancy at birth in most high-income countries (US roughly 78 to 79, Japan and Switzerland around 84). Move the slider to your own estimate; if you have already reached a given age, your remaining expectancy is higher than the at-birth figure.
What is a 10,000-day birthday?
Your 10,000th day alive falls about 27 years and 4.5 months after birth, your 20,000th day at about 54 years and 9 months, and your 30,000th at about 82 years. This tool lists the exact dates so you can mark them; they do not fall on a normal birthday.