The average human lifespan
4,000 weeks
That's it. That's the whole thing — school, work, love, summers, Tuesdays. The number sounds impossible until you see it drawn.
The idea
Oliver Burkeman's Four Thousand Weeks begins with a blunt observation: the average life is absurdly, insultingly finite — and pretending otherwise is how we lose it. Tim Urban's essay Your Life in Weeks made the same point with a picture. A life isn't an ocean of time; it's a grid you can fit on one sheet of paper.
The strange thing is what the picture does. People expect it to feel morbid. Instead it feels clarifying — suddenly this week, the one you're in, is visibly one of a limited edition.
See your own
The calculator draws your 4,000 weeks free in ten seconds. The Mac app keeps the picture on your desktop, marking off one circle every Monday, forever.
The number, checked
Four thousand is the round version: 76.9 years is exactly 4,000 weeks, and world life expectancy sits within a year of it. An 80-year life is 4,175 weeks; 90 years is 4,695. Pick your own horizon on the life expectancy calculator and the grid redraws to match — the argument doesn't depend on the digit.