Dimensional weight reflects the amount of space a package occupies in relation to its actual weight. Often referred to as “Dim weight”, pricing is based on volume instead of the actual weight of the shipment. The dimensional weight is calculated by multiplying the length, weight, and height of a package and dividing that number by 139. For example, the dimensional weight of a package with the following dimensions 25X6X43/139 = 46.40 Pounds. You will be charged 47 lbs.