The Chargeable Weight of Air Freight shipments are calculated as the Actual Weight (Gross Weight) or the Volumetric (also called Volume or Dimensional) Weight of the shipment, whichever is the greater. This uses an estimated weight that is calculated based on the dimensions (length, width and height) of a package (shipments are always shown in the order of L x W x H). Typically, large items with a light overall weight take up more space on an aircraft than a small, heavy item. That’s why the Airlines charge according to Chargeable Weight.
Chargeable weight is commonly used by air freight forwarders, domestic motor carriers and brokers to calculate their air freight and/or domestic trucking charges.
For those of you who simply want the formulas without a detailed explanation, here you go:
The formula for calculating the volume/dimensional weight for all commodities is 166 cubic inches per pound or 6000 cubic centimeters per kilogram or 366 cubic inches per kilogram.
Multiply the length by the width by the height to obtain the cubic inches, then:
Some definitions and formulas to start:
Chargeable Weight: the greater of actual weight vs. volume weight of a shipment. Chargeable weight is an equilibrium point where the actual weight and volume weight of cargo balance out for the airline, BUT, keep in mind that if the actual weight of the cargo is higher than the “equilibrium point”, the air freight charges are billed on that actual weight.
Volume/Volumetric/Dimensional Weight: Cargo weight based on dimensions of the cargo
Actual Weight: Actual weight of the cargo weighed on a scale
Lb or lbs: pounds
Kg or kgs: kilograms
Cft or ft3: cubic feet
Cbm or m3: cubic meters
Tonne or mt: metric ton 1,000 kgs / 2,204.6 lbs
1 inch = 2.54 centimeters (cms) / 1 cms = 0.393701
1 lbs = 0.453592 kgs / 1 kgs = 2.20462 lbs
Imperial shipping factor examples:
167 in3/lb = 10.4 lb/ft3
Metric shipping factor examples:
5000 cm3/kg = 200 kg/m3
6000 cm3/kg = 166.667 kg/m3
7000 cm3/kg = 142.857 kg/m3
Note: all dimensions and weights are rounded to the nearest whole number.
Combining dimensions in inches and weight in kgs: (L x W x H)/366 (this is commonly done in U.S. exports since dimensions are provided in inches but charges for air freight are always in kgs)
Freight Rate, the cost of transporting goods, is reflective of a number of factors aside from normal transportation costs. The main determining factors of freight rate are: mode of transportation (truck, ship, train, air craft), weight, size, distance, points of pickup and delivery, and the actual goods being shipped.
Mass is a measure of the matter within a body. Volume is the quantity of space a body occupies measured in liters and milliliters in the metric system and ounces and pounds in the English system. The same volume of two different substances, may have different weight and mass.