On Sun, 4 Mar 2012 01:02:03 +0000, ExcelNoob123 wrote:


I have created a sheet which is tracking 3 items per client and a number
of clients so I have set up a SUM function the only way I know how which
is a long a1+a4+a7, etc
Its works fine, but if I want to add a new client and 3 new rows, ALL of
the + after are now off.

Is there a better way to create a formula that will track say every 3rd
cell in a column but then let you lengthen or shorten the column?

Thanks!!

One way, by setting a range greater than your expected number of entries.
FirstRow is the first row number that you want to add. e.g. 1 for A1, A4, A7, etc
2 for A2, A5, A8, etc.

=SUMPRODUCT((MOD(ROW($A$1:$A$1000)-FirstRow,3)=0)*$A$1:$A$1000)