FF3 Monster Damage Excel Spreadsheet

You've already got the right idea of it in that 125 PDef cuts damage roughly in half. That formula you have is the base damage, and then the defense formula that I posted reduces the damage according to the physical defense of the target. In that example where you have the base damage value of 879, if an enemy hits a target with 190 PDef, it will deal 65/255 damage, or about 224.