“Chargeable weight” is a concept in freight shipping used to calculate the cost of transporting goods based on the actual weight (gross weight) and space occupied (volumetric weight) by the shipment to cover the carrier’s expenses. As such, shipping 1 kg of cotton may cost more than 1 kg of iron because it takes up more space.
Chargeable weight formulas are as follows:
Gross weight = cargo + packaging + pallets
For example, Gross weight = 120 kg (if the cargo weighs 100 kg + packaging + pallet weighs 20 kg)
Volumetric weight (also known as dimensional weight) = (length x width x height) / DIM factor
For instance, for a shipment dimension of 50cm x 40cm x 30cm, using a common DIM factor of 5000 for air freight, the volumetric weight is (60000)/5000 = 12 kg
The DIM Factor converts volume to weight, and varies according to the transport mode and the carrier. Carriers set it to ensure adequate revenue contribution from bulky, light items.
Finally, Chargeable weight = The greater the gross weight / the volumetric weight.
Using the earlier examples:
Gross weight at 120 kg vs volumetric weight at 12 kg
The chargeable weight = 120 kg.