Volumetric weight, sometimes called "dim" or dimensional weight, is used when the space a shipment takes on an aircraft may cost more than the shipment's actual weight.
You should calculate dimensional weight on every shipment, compare that to its actual weight, and use the greater of the two to determine your shipping cost. Volumetric weight for international shipments is calculated using the formulae below. Volumetric weights for domestic shipments may vary, so please contact Customer Service department.
Length x Width x Height in centimeters (cm) / 5,000 = Volumetric Weight in kilograms rounded up to the nearest 0.5kg
Length x Width x Height in inches / 138.4 = Volumetric Weight in pounds rounded up to the nearest pound.
How to Calculate A Dimension Weight