This is an array formula, meaning you enter it with Shift+Ctrl+Enter

=MAX(IF(A1:A6=D1,B1:B6,0))

where the Item #s are in A1:A6 and the item# you're interested in is in D1


"eoht" wrote:

I have 2 columns of data; my item number and amount of quantity reserved. I
want to be able to get the max of a quantity reserved by looking up the item
number. For example, I want to find out the max on Quantity for Item #100 =
10.

Item # Quantity
101 5
100 10
102 4
100 8
102 9
101 11