I see one issue. I'm not sure how SUMPRODUCT deals with a multiple column reference such as ('SPT FCST'!$E$1:$R$1='Overview 2017'!$F$3).

I think you may have better luck with column headings such as Nov 16, Dec 16, Jan 17, etc.

Then you could use the offset command to point to the correct column using Match.

http://www.utteraccess.com/wiki/inde...Dynamic_Ranges

Also you might consider using Excel Tables.

http://www.utteraccess.com/wiki/inde...ables_in_Excel

Two of the advantages of tables to this issue are (1) tables know how big they are, so you don't have to guess at which row you need to stop. Formulas based on tables use all of the data they need and no more and (2) Formulas based on tables use the table header name instead of Row/Column addresses. You may be able to use this feature in conjunction with INDIRECT to match the table header on the Overview sheet with the table header on the SPT FCST Sheet. This should eliminate the need for OFFSET and MATCH.

For example if Cell F7 on the Overview sheet contained "Feb 17" and the name of the table on the SPT FCST sheet is Table_FCST then the formula may contain =SUMIFS(INDIRECT("Table_FCST["&F7&]"), ...)