Air cargo chargeable weight explained: actual vs volumetric weight

When shippers receive an air freight quote, a common question is why the price is higher than the actual weight suggests. Air freight is charged on whichever is greater: the cargo's actual weight or its volumetric weight, which converts size into weight. That figure is called the chargeable weight.

Volumetric weight is the length, width and height of each carton in centimetres multiplied together and divided by 6,000. This is the standard divisor in international air cargo, and it means one cubic metre counts as roughly 167 kg. Express couriers often divide by 5,000, so the same box can be charged heavier when sent by courier.

For example, a carton measuring 60 × 50 × 40 cm with an actual weight of 12 kg has a volumetric weight of 60 × 50 × 40 ÷ 6,000 = 20 kg. The chargeable weight is the larger figure, 20 kg, and ten such cartons would be charged at 200 kg. (Figures are an illustration only.)

Light, bulky goods such as clothing, food packed in polystyrene or exhibition stand materials are usually charged on volumetric weight. Small, dense cargo such as machine parts or metal products is usually charged on actual weight.

To lower the cost, cut empty space inside the packing, keep carton sizes uniform when sending several, and stack pallets lower. Air rates are banded by weight, for example +45 kg, +100 kg and +300 kg, with a different rate per kilogram in each band, so being charged in the next band up can sometimes reduce the total. For bulky cargo, compare the cost and transit time of sea LCL as well.

On top of the air rate, airlines add fuel and security surcharges (FSC and SSC), and handling charges at origin and destination and customs fees apply separately. When comparing quotes, check whether these are included, not only the freight rate.

On the KALTSTART website, the instant quote shows the reference rate per kilogram for listed routes as soon as you pick the departure and arrival airports. Request a detailed quote with your carton sizes and quantity and we will calculate the chargeable weight for you; after booking, you can follow the flight's progress in Track Cargo.