A billing technique employed by shippers to take into account the volume rather than the weight of high volume, low weight shipments. Traditionally, shipments were billed on a weight basis: x cost per unit of weight measure. This works well for shipping companies in cases where the commodity shipped has a high density; for example, industrial machinery. However, other commodities, such as hats, consumer electronics, luggage, and clothing, have a relatively low density. This can be a problem, for example, for air cargo companies where volume is an important factor. Hence, the dimensional weight rule was developed by shippers as a practice applicable to low density shipments under which the transportation charges are based on a cubic dimensional weight rather than upon actual weight. The shipping company will calculate freight based on the higher of the two rates.
Dimensional weight has different definitions based upon whether the shipment is domestic or international, the carrier, and the commodity shipped.
Dimensional Weight, Domestic US Shipments.
L x W x H / 194 = DW
Dimensional Weight, International Shipments: L x W x H / 166 = DW
Examples: Dimensional weight equals one pound for each 194 cubic inches in the case of most domestic air freight, one pound for each 166 cubic inches of most international shipments, and one pound for each 266 cubic inches of cut flowers or nursery stock shipments. The dimensional weight system is used by almost all air freight forwarders, trucking companies and airlines worldwide. In 2007 all the major courier companies adopted dimensional weight calculations for ground services.