To find your age in weeks, count the days from your date of birth to today and divide by 7: the whole number is your age in weeks and the remainder is the extra days. For example, someone born on June 15, 1990 is 1,898 weeks old on October 30, 2026 — exactly, with no days over.
The calculator also tells you which week of your life you are in, when you reach your next 1,000-week milestone, and draws your life as a grid of weeks, one row per year.
Worked example
Date of birth: June 15, 1990Count to: October 30, 2026
Weeks old on Oct 30, 2026: 1,898 weeks
13,286 days divided by 7 is exactly 1,898, so that day is the start of week 1,899 of their life.
Open this example in the calculator →How to use the Age in Weeks Calculator
- Enter the date of birth — yours, or a baby's.
- Leave "Count to" as today, or choose another date.
- Read the age in weeks and days, the week of life and the next 1,000-week milestone.
- Scroll down to see the life-in-weeks grid filled in to today.
How to calculate age in weeks
Weeks are the one unit of age with no awkward edges: every week is exactly seven days, whatever the month or year. So the method is simply:
- Count the days between the date of birth and today (the age in days calculator does this).
- Divide by 7. The whole number is the age in weeks.
- The remainder, 0 to 6, is the extra days.
Born June 15, 1990 and counting to October 30, 2026: 13,286 ÷ 7 = 1,898 with nothing left over, so the answer is 1,898 weeks exactly. The next day begins week 1,899 of that person's life.
Weeks for babies
For the first months, babies' ages are usually given in weeks, because development changes so fast. A baby born on September 1 is 8 weeks and 4 days old on October 31. Pediatricians usually switch to months at around 3 months, and to years and months after the first birthday. For a premature baby, the baby age calculator also works out the corrected age.
Your life in weeks
The grid draws a 90-year life as 4,680 squares: 90 rows of 52 weeks. Seeing the weeks already lived beside the ones still to come is a well-known way to think about how to spend time — the idea behind Oliver Burkeman's book Four Thousand Weeks, named for the length of an average human life. Four thousand weeks is 28,000 days, or about 76 years and 8 months.
Weeks in a year
A common year is 52 weeks and 1 day; a leap year is 52 weeks and 2 days. That is why a birthday falls one weekday later each year — two after a February 29 — and why the grid's rows, at 52 squares each, round every year down very slightly.
Frequently asked questions
How many weeks old am I?
Enter your date of birth and the calculator divides the days you have lived by 7. For example, someone born on June 15, 1990 is 1,898 weeks old on October 30, 2026.
How many weeks are in a year?
52 weeks and 1 day in a common year, and 52 weeks and 2 days in a leap year. On average a year is about 52.18 weeks.
How old is 1,000 weeks?
1,000 weeks is 7,000 days, which is about 19 years and 2 months. 2,000 weeks is about 38 years and 4 months.
What does "week of life" mean?
It counts the week you are in now, starting from week 1 at birth. If you are 1,898 weeks old exactly, you are at the start of week 1,899.
How many weeks old is a 3-month-old baby?
About 13 weeks. Three calendar months is 89 to 92 days depending on the months, so between 12 weeks 5 days and 13 weeks 1 day.