I'm trying to figure out how to subtotal sum the units of a department only once if they are duplicated. Column I shows the complete department (column D) units for the date range shown in columns B & C, cells I4 through I6 are duplicate values of the same total which is 11 for the Grocery Department, cells I7 through I9 are the duplicate values of the same total which is 6 for the Dairy Department, etc. The formula in cell I2 is currently '=SUBTOTAL(109,I4:I31)' which sums anything that is not filtered but I can't figure out what to add to this formula so that it only sums the department total once and skips over any duplicate values, the desired formula would return 38 instead of 126. I've searched the forums and cannot seem to find anything regarding this so any help is greatly appreciated.