Systems and methods for determining a Q value for a subsequent inventory round can include a radio frequency identification (RFID) interrogator determining at least one of: a number of empty slots, a number of collided slots, and a number of singly occupied slots, in response to the completion of an inventory round, and applying a function to at least one of: the number of empty slots, the number collided slots, and the number of singly occupied slots, to determine the Q value.