Hi,

If the data were contiguous one would use something like

=SUM(OFFSET(C1,COUNT(C:C)-1,,-12))

in your case try

=SUM(E22:E33,OFFSET($E$5,COUNT(E22:E33),,12-COUNT(E22:E33)))
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If this helps, please click the Yes button.

Cheers,
Shane Devenshire


"MH" wrote:

Hi,
I have searched to message boards and can't quite find what i'm looking for.
I'm trying to keep a 12 month running tally (When I enter the information
for a new month, the oldest month drops out keeping only 12 months of
information)

I currently have a worksheet with 2 matrixes of information.

A5-A16 holds the months of 2008 (Jan, Feb,...) and E5-E16 holds the monthly
totals.
A22-A33 hold the months of 2009 and E22-E33 holds the montly totals.

In a cell (F39 on my worksheet) I'd like to keep the 12 month rolling total
such that when I enter the data for June, the total in F39 will update for
the period of Jun09-Jul08.

Thanks for any help.