After rereading your problem statement, assuming B2 will contain a value
between 1 and 12 inclusive:

=SUM(OFFSET(B2,0,B2,1,3))



--
Regards,
Tom Ogilvy

Tom Ogilvy wrote in message
...
=SUM(OFFSET(C2,0,MATCH(TRUE,C2:N20,0)-1,1,3))

--
Regards,
Tom Ogilvy

John wrote in message
om...
Sorry, but I thought I'd be able to figure out the "real" formula
after getting something to work with from here. Frank, do you or
anyone else have a suggestion as to how to modify your formula to get
work with this exact data:

Product, StreetDate, Month1, Month2, Month3..Month12,
Initial_3month_Activity

Where Initial_3Mo_Activity sums the three contiguous month values
starting at the Month# corresponding to its StreetDate (instead of the
first positive Month value).

Any tips are greatly appreciated! (I may need to repost this as a new
thread if there aren't any responses since this has nothing to do with
SUMIF.)

(Frank's formula:)
=SUM(OFFSET(B2,0,MATCH(TRUE,B2:M20,0)-1,1,3))

-j



"Frank Kabel" wrote in message
...
Hi John,
Some assumptions: Your products are listes in column A and your month
are listed in row 1. So the activitie for the first product in the
first month would be listed in cell B2. then try the following formula
for the first product in row 2:
=SUM(OFFSET(B2,0,MATCH(TRUE,B2:M20,0)-1,1,3))
enter this as array formula (CTRL+SHIFT+ENTER)

HTH
Frank



John wrote:
I'm building a sheet that lists product units over a twelve month
period. I want to calculate the SUM of the first three months where
there's been activity...find the first cell within the twelve month
range that has a positive units sold value and sum that cell with
the
next two adjacent cells, which can be either positive or negative.
(The initial cell must be positive.)

Any tips on how to build this a formula for this are greatly
appreciated!