By: John

What if I wanted to sum the value of all Lenovos and all desktops in the month of June without double-counting the Lenovo desktop sold in that month? The total should be 70,700, but if I add the total of all Lenovos for the month of June and all desktops for the month of June, it ends up as 77,280 (this is taken from the table in the second, third, and fourth screenshots of the section entitled 'Use of SUMIF with INDEX-MATCH Functions to Sum under Multiple Criteria'), because the Lenovo desktop in June (6,580) gets counted twice. How can we avoid this double-counting and use a formula that would arrive at the total of 70,700 (and could it be used if there was a third criterion--OR not AND--that we wanted to sum without double and triple counting the instances where more than one of these criteria was met)?