The unit price of an item is the cost for each unit. The unit price may be calculated for several reasons. It will allow an easy comparison of the cost of the same quantity of items that come in different sizes. It may be used to find the cost of a single item when many items are purchased together. This may be required if the items are going to be resold or divided among several people with each person paying their fair share of the cost based on how many items they receive.