Life in Weeks Calculator
See your whole life on one page: 4,680 dots, one for every week of a 90-year life, with the weeks you have lived filled in.
- Free forever
- Instant results
- Private — runs in your browser
How to use the Life in Weeks calculator
- Enter your date of birth.
- Tap Show my life in weeks. Each row of the grid is one year of your life and each dot is one week — 90 rows × 52 dots = 4,680 weeks.
- Filled dots are weeks you've already lived; the pulsing dot is this week. Share the card, or send the link so friends can compare.
The idea comes from Tim Urban's "Your Life in Weeks" essay on Wait But Why: seeing a whole lifetime on one page makes time feel finite in a motivating — not scary — way.
History & interesting facts
Did you know?
A 90-year life is only about 4,700 weeks — few enough to fit on a single sheet of paper.
Origin & history
Tim Urban popularised the life-in-weeks chart in his 2014 Wait But Why post, and Oliver Burkeman's 2021 book "Four Thousand Weeks" took its title from the same arithmetic. Global life expectancy at birth was about 73 years in 2023 (UN World Population Prospects 2024), and in many countries it is well over 80 — so 90 years is a generous, round upper bound rather than a forecast.
Fascinating facts
- 1
A synodic month (full moon to full moon) lasts about 29.53 days, so a 30-year-old has seen roughly 370 full moons.
- 2
Sleeping 8 hours a night means about a third of all those dots are spent asleep.
- 3
Each row starts on your birthday, so the pulsing dot moves one step to the right every week.
Frequently asked questions
How many weeks are in a 90-year life?
About 4,680 if you count 52 weeks per year (90 × 52). Counting the extra day or two each year, it is closer to 4,696 weeks — the grid uses 52 per row so every year lines up neatly.
How do I calculate how many weeks I have been alive?
Count the days between your birth date and today, then divide by 7 and round down. This calculator does exactly that, using calendar dates so time zones and daylight saving cannot shift the answer.
Why does the chart stop at 90 years?
It follows the classic Wait But Why life calendar. 90 is a generous round number — above average life expectancy in almost every country — not a prediction of how long you will live. If you are past 90, the whole grid fills up and every extra week is a bonus.
What does "summers left" and "weekends left" mean?
They are counted up to age 90: summers left is the number of full years until your 90th birthday, and weekends left is the number of remaining weeks on the grid. They are a playful way to picture time, not a forecast.
Is my birthday stored anywhere?
No. The calculation runs entirely in your browser. Your date of birth only appears in the page link if you share it, so anyone you send the link to will see the same chart.