how do i calculate a 4 week rolling average

[Guest]

How do i get excel to calculate and display a 4 week rolling average? I have
the dates of each week in column A, the sales data is entered in column B. I
am not sure if I need to use Today's date to generate the average or if I can
just get Excel to drop the 1st week when I enter a new sales figure. If
anyone has an understandable formula it would be most appreciated!

 

[Dave O]

You said each row contains a total of sales data for the week, and
resides in column B. Assuming your first entry starts on row 1, to get
a 4-week rolling average you could simply use this formula in C4:
=SUM(B1:B4)/4
When you copy and paste that to the next row, the cell references will
shift, and consider only those 4 weeks of data.

Does that do what you need it to do?