Week numbers in Google Sheets

How to get the week number from a date

To get the ISO week number (1-53) from a date in cell A1, use =ISOWEEKNUM(A1).

To get the corresponding year, use =YEAR(A1-WEEKDAY(A1, 2)+4).

Read more about =ISOWEEKNUM() and WEEKDAY() in the Google Docs Help Center.

How to get the date from a week number

To get the date of the Monday in a week, use =DATE(A1, 1, -3 + 7 * B1 - WEEKDAY(DATE(A1, 1, 4), 2) + 1).

Cell A1 contains the four-digit year (e.g. 2024), and cell B2 contains the week number (1-53).

How to get the number of weeks in a year

To get the number of ISO weeks in a year (i.e. the number of the last week), use =ISOWEEKNUM(DATE(A1, 12, 28)).

Cell A1 contains the four-digit year (e.g. 2024).

Read more

Learn more about week numbers and the ISO week numbering scheme in this little primer.