If you have headers and data starts from row 2 ; in row 31 insert the formula
and copy down as required...In the below example it average the values of Col
B

=AVERAGE(INDIRECT(ADDRESS(ROW()-29,1) & ":B" & ROW(B31) ))

If this post helps click Yes
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Jacob Skaria


"Chris" wrote:

I'm logging data into a spreadsheet daily and keeping track of a rolling 30
days average and 1 std dev above the average. How do I easily create a way
to update this everyday without changing the formula every day? I have dates
on the left and numbers (25, 32, 28, etc.) next to the date. Thanks.