6 that the CountIf formula cell shows does not answer OP's question since OP qualifies the result from the Sum array formula as correct. Rather, the CountIf formula calculates how many cells in the A range is smaller ( < ) than each value in the B range, which results in an array whose size is equal to that the criteria range. Since the result is an array, the formula cell displays the first item of the result array (it cannot do otherwise). Hence 6.