Each enemy unit that has half or less of their starting Unit Strength left at the end of the battle is worth a number of victory points equal to 50% of the number of points it cost to include the unit in the army.
Source: Warhammer Armies Project
Each enemy unit that has half or less of their starting Unit Strength left at the end of the battle is worth a number of victory points equal to 50% of the number of points it cost to include the unit in the army.