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Sizewise Life in Weeks

Your life as a grid of weeks: one row per year, with milestones and exact counts.

More options

For example “2012-09-01 First job”.

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More about this tool

How it works

Draws a life-in-weeks grid from a birth date — one row per year, 52 boxes per row — with the current week, your milestones and exact counts of days, weeks, Sundays and leap days lived. Nothing is stored.

  • Rows start on each birthday (29 February birthdays fall on 28 February in common years); box n of a row covers days 7(n−1) to 7n−1 after the birthday, and the 52nd box also holds the last one or two days of the year.
  • Days, Sundays and leap days are exact counts of UTC calendar days from the birth date to the chosen day, both included for Sundays and leap days. Full Moons are days lived ÷ 29.530589 (mean synodic month, Meeus).
  • The grid length is your choice (90 years by default); it is not a life-expectancy estimate.

Nothing you enter is stored on the server beyond the request itself. The grid is a way to picture time, not a prediction.

Sources

  • Astronomical Algorithms, 2nd ed. (Meeus 1998) (Willmann-Bell)

Part of Sizewise

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    Make sizes, amounts and big numbers feel real: to-scale lineups, fit counts and stacks.

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How to use Sizewise Life in Weeks

Draw a life as a grid of weeks from a birth date, mark milestones and get exact counts of days, Sundays, leap days and Full Moons lived.

What it is for

A life drawn as boxes — one row per year, one box per week — fits on a single page and makes time visible in a way a number cannot. Life in Weeks draws that grid from a birth date, fills the weeks already lived and marks the current week and any milestones you add.

Alongside the grid it counts days, weeks and months lived, Sundays, leap days and Full Moons, the boxes left in the grid and the days to the next birthday. It suits reflection, birthday cards, retirement speeches and classroom discussions about time.

The number of rows is your choice (90 by default). It is not a life-expectancy estimate.

Worked example

The first example is someone born on 15 June 1990, counted to 8 November 2026. The summary reads: On 2026-11-08 you are in week 21 of year 37: 1899 weeks lived, 40.4 % of a grid of 90 years.

The counts are 13,295 days lived, 1,899 weeks, 436 months, 1,900 Sundays, 9 leap days (1992 to 2024) and about 450 Full Moons. 2,787 boxes are left, and the next birthday is 2027-06-15, in 219 days.

With the milestones 1996-09-02 First day at school and 2008-07-01 First job, the table places school in year 7, week 12, and the first job in year 19, week 3. Both show as orange boxes in the grid.

The second example is a leap-day birthday, 29 February 2000. Its rows start on 28 February in common years, so on 8 November 2026 the person is in week 37 of year 27, and the next birthday is 2027-02-28.

How to read the result

  • Week n of year m is the box for the chosen day: rows start on each birthday, boxes are 7-day steps from it, and the 52nd box also holds the last day or two of the year.
  • Days lived, Sundays and Leap days are exact counts of calendar days.
  • Months lived counts full calendar months since the birth date.
  • Full Moons (about) divides the days by the mean synodic month of 29.53 days (Meeus), so it can be off by one.
  • The SVG grid uses grey for lived weeks, pale boxes for the future, pink for this week and orange for milestones.

Tips and common mistakes

  • Leave Count up to empty for today, or set a date to see the grid at a past or future moment.
  • Write milestones as YYYY-MM-DD label, one per line. A date before the birth date is reported as an error; milestones after the last row stay in the table but not in the grid.
  • Each row has 52 boxes even though a year has 52 weeks and one or two days; that is why year rows start on the birthday and not on a Monday.
  • In the Sizewise app the birth date stays in your browser and share links leave it out.

FAQ

Why does my week number not match the calendar week?

The grid counts weeks from your birthday, not ISO calendar weeks from 1 January.

What happens with a 29 February birthday?

In common years the new row starts on 28 February.

Is the birth date stored?

The tool computes the result for your request only. In the app it stays in this browser and in project files you save.

Can I print the grid?

Yes. Download the SVG, or use the Life in weeks view in Sizewise and print it.

Guide last updated:

For scripts and AI agents

  • JSON API: POST https://sizewiselifeweeks.usefulweb.app/api/v1/calculate (same calculation as this page)
  • Interface description: OpenAPI 3.1 · AI guide: llms.txt
  • MCP server (Streamable HTTP): https://sizewiselifeweeks.usefulweb.app/mcp · tool name sizewise_life_weeks
Example request
curl -s -X POST https://sizewiselifeweeks.usefulweb.app/api/v1/calculate \
  -H 'content-type: application/json' \
  -d '{"birthDate":"1990-06-15","today":"2026-11-08","years":90,"milestones":"1996-09-02 First day at school\n2008-07-01 First job"}'
Feedback · ideas & bug reports welcome