CBM is primarily used in shipping to make the following critical calculations for all modes of transport:
Dimensional weight
Dimensional weight is used for ocean shipments where volume is the primary focus. It is calculated as follows:
Dimensional weight (kg) = CBM / Dimensional weight factor
Dimensional weight factor (DIM factor) is the volume of cargo allowed per unit of weight. To simplify and standardize freight pricing, different modes of transport use varying weight standards for 1 CBM.
Chargeable weight
Chargeable weight is used for light shipments that may take a lot of space, critical for air freight. For example, a pallet of inflatable pool toys might take up the same space as a pallet of metal pipes, but the weight difference is substantial. It factors in the calculated dimensional weight and is represented as:
Chargeable weight (kg) = Max(Actual weight, Dimensional weight)
The shipment will be charged based on whichever weight is greater.
Freight class
This system is primarily used in the US to categorize goods transported through Less Than Truckload (LTL) shipping. The freight class is determined by factoring in the CBM and weight of the shipment. For example, a pallet of inflatable pool toys takes up a volume of 1 CBM. Let’s say the total weight is 10 kg. First, we calculate the density, which amounts to 10 kg/m3 or 0.62 lb/ft3. This falls under class 500 i.e., packages under 1 lbs. per cubic feet, reflecting the highest applicable charges.