How do i convert days to weeks in excel?

Summary 

To get the week number from a date, you can use the WEEKNUM function. In the example shown, the formula in C5, copied down, is:

Explanation 

The WEEKNUM function takes a date and returns a week number (1-54) that corresponds to the week of year. The WEEKNUM function starts counting with the week that contains January 1. WEEKNUM takes two arguments: a date, and (optionally) return_type, which controls the scheme used to calculate the week number. 

By default, the WEEKNUM function uses a scheme where week 1 begins on January 1, and week 2 begins on the next Sunday (when the return_type argument is omitted, or supplied as 1). With a return_type of 2, week 1 begins on January 1, and week 2 begins on the next Monday. See the WEEKNUM page for more information.

ISO week number

ISO week numbers, start on the Monday of the first week in a year with a Thursday. This means that the first day of the year for ISO weeks is always a Monday in the period between Jan 29 and Jan 4. Starting with Excel 2010, you can generate an ISO week number using 21 as the return_type:

Starting in Excel 2013, there is a new function called ISOWEEKNUM.

For more details, see Ron de Bruin's nice write-up on Excel week numbers.

Related formulas 

In this example, the goal is to get the day name (i.e. Monday, Tuesday, Wednesday, etc.) from a given date. There are several ways to go about this in Excel, depending on your needs. This article explains three approaches: Display date with a custom...

The MONTH function takes just one argument, the date from which to extract the month. In the example shown, the formula is: = MONTH ( B4 ) where B4 contains the dateJanuary 5, 2016. The MONTH function returns the number 1 representing the month(...

The YEAR function takes just one argument, the date from which you want to extract the year. In the example, the formula is: = YEAR ( B4 ) B4 contains a date value for January 5, 2016. The YEAR function returns the number 2016 representing the year...

Related functions 

The Excel WEEKNUM function takes a date and returns a week number (1-54) that corresponds to the week of year. The WEEKNUM function starts counting on the week that contains January 1. By default, weeks begin on Sunday, but this can be changed.

The Excel ISOWEEKNUM function takes a date and returns a week number (1-54) that follows ISO standards, where weeks begin on Monday and week number 1 is assigned to the first week in a year that contains a Thursday.

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