Had a user today call saying the Excel spreadsheet they created was calculating the SUM of invisible/hidden rows/columns. The problem was..they didn’t want Excel calculating the SUM of hidden rows and columns. A quick Google told me the SUBTOTAL function calculates the the sum of visible data and ignores invisible data. ALSO, from what I have read, this ONLY works with filtered data.
So the answer is use the SUBTOTAL function for calculating the sum of data in visible cells, rows, and columns.