Continuing the SUMMATION for a x- number of cells

Using Excel 2007

Column A: I have 90 continuous rows filled with numbers

Column B:

Row 1 = SUM (A1:A30)

Row 2 = SUM (A31: A60)

Row 3 = SUM (A61:A90)

In short, I want to find the sum of the first 30 rows, next 30 rows and so forth.

Since in reality I have many more rows than 90 rows, I will like a way that allow me to pull and drag down Colimn B instead of entering the syntax for each cell.

Thank you.

Put this in B1:

=SUM(INDEX(A:A,(ROWS($1:1)-1)*30+1):INDEX(A:A,ROWS($1:1)*30))

then copy down.

Hope this helps.

Pete

Thank you for the reply. But if I wish to vary the formula

For eg, if

Column D: I have 90 continuous rows filled with numbers

Column J:

Row 12 = SUM (D12:D41)

Row 13 = SUM (D13: D42)

and so forth

Then how should I change the syntax for the above given formulas.

Thank you

That isn't the same problem as you outlined originally. If you put that formula in J12, i.e.:

=SUM(D12:D41)

then copy it down then you will have what you describe in the next cell.

Maybe I'm missing something.

Pete

Sorry I made a typing error, it should be

Row 12 = SUM (D12:D41)

Row 13 = SUM (D42: D71)

and the next 30 rows and so on.

Thank you

Okay, so you still have a span of 30 cells, but you want the first one to start with row 12, then 42, then 72, and so on, and it is column D rather than column A that you want to sum. In that case you can change my formula (in J12) to:

=SUM(INDEX(D:D,(ROWS($1:1)-1)*30+12):INDEX(D:D,ROWS($1:1)*30+11))

Then copy down.

Hope this helps.

Pete