Home / Learn
Learn
The math and ideas behind the numbers — life expectancy, exact age, and why time is worth paying attention to.
How is life expectancy actually calculated?
Life expectancy figures aren't predictions about you — they're a statistical summary of an entire population. Here's the actual math behind the number.
Why your exact age isn't just "years since your birthday"
Calculating your age down to the day sounds simple until you hit leap years, months of different lengths, and the question of what a "day" even means across time zones.
Why seeing your life as a grid of weeks changes how you think about time
A 90-year life is about 4,680 weeks. Laid out as a grid, most of it is already gone or already spoken for — here's why that visualization is so unsettling, and so useful.
The longest verified human lifespans on record
Jeanne Calment's 122 years remains the oldest fully documented human age ever recorded. Here's what the verified record actually looks like — and why so many longevity claims don't hold up.