First, anyone and everyone that can help me it is much appreciated. I am a new user here with some level of Excel experience--just not advanced by my standards. I will try to be as descriptive as possible.

Background:

I extract a list of raw data each month from Access that I aggregate into one master Excel file. The excel file is organized by Calendar Reporting month/Platform/etc (see attched). The formula I have in column I is =(SUMIFS(H:H,B:B,C3,F:F,F3,G:G,G3)-SUMIFS(H:H,B:B,E3,G:G,G3)). It works for the first two rows but not after.

Issue:

I would like to create an 'IF' or ‘SUMIF’ function (if possible) that detects the current month’s ISBN count figure (Column "I") that would automatically subtract the prior month’s ISBN count by Role_ID (Column G). The calculation is analogous to a waterfall...I need to automate each prior month variance for both Role ID/

Purpose:

This is intended to easily automate my calculations (current month – prior months) usage in Column I. I am currently doing this manually.

Please see attached file

thanks