Calculate age in weeks from a birth date to see how many weeks and days old a baby, child or adult is today or on any other date you choose.

Uses calendar dates, without a birth time.

Calculation date (optional)
Blank means today. The result shows the date actually used.

Age By Weeks Formula

The following equation is used to calculate the total number of weeks lived.

W = D / 7
  • Where W is your age in weeks
  • D is the number of calendar days from birth date to calculation date
  • The birth date is excluded from the elapsed-day count; equal dates give zero
  • Each week contains 7 calendar days; leap days are included

Enter your birth date and select Calculate. Under Calculation date (optional), enter a date or leave it blank to use today on your device. The calculator counts calendar days between the dates and divides by seven; time of day and daylight-saving clock changes are not included.

What is an Age By Weeks Calculator?

Definition:

The Age By Weeks Calculator is a tool that computes the total number of weeks you have lived based on your birth date and a specified calculation date.

How to Calculate Age in Weeks?

Example Problem:

The following example outlines the steps and information needed to calculate your total weeks lived.

First, determine your birth date. In this example, it is January 1, 1990.

Next, determine the calculation date. In this example, it is January 1, 2020.

Finally, calculate your age in weeks using the formula above:

W = calendar days elapsed / 7

W = 10,957 / 7

W ≈ 1,565.2857 weeks

FAQ

What is the Age By Weeks Calculator used for?

The Age By Weeks Calculator is designed to help you determine the total number of weeks you have lived based on your birth date and a specified calculation date, typically the current date.

How does the calculation work?

The calculator counts calendar days between the birth date and calculation date, including leap days, then divides by seven. It also shows complete weeks and remaining days. A restored result keeps the original calculation date; select Calculate again to update a blank date to today.

What should I do if the calculation date is before my birth date?

If the calculation date entered is before your birth date, the calculator will show an error beside the date, as the calculation date must be the same as or after your birth date.