Large items with a light overall weight are charged according to the space they take up on aircraft. In these cases, Volumetric Weight, or dimensional (Dim) weight, is used to calculate the shipment cost. It is recommended that you calculate the Volumetric Weight for every shipment that you send, then compare this to its actual weight. The greater weight of the two is used to work out the price that we charge you. International Volumetric Weights are calculated using the formula below: (Length x Width x Height in centimeters) / 5000 = Volumetric Weight in kilograms