Cubic weight: why your pallet costs more than it weighs.

What it is, and why

Carriers charge based on the higher of two values: actual weight or cubic weight, which is calculated from the space your freight occupies. For light, bulky items, cubic weight often exceeds actual weight. As a result, a pallet of pillows may cost as much to ship as a pallet of paint, despite the difference in mass.

This approach is logical. A truck reaches either its floor space or weight capacity first. Dense freight hits the weight limit before filling the space, while light, bulky freight fills the space before reaching the weight limit. Cubic weight allows carriers to price shipments based on space used, ensuring costs reflect actual usage.

The factor isn’t fixed

Cubic weight is calculated by multiplying your consignment’s volume in cubic metres by a conversion factor. This factor varies and can greatly affect your charges.

In Australia, parcels are typically charged at 250 kilograms per cubic metre. Pallet carriers may use 250 or 333, depending on the carrier and route. Freight to Tasmania often uses a 1000 factor due to sea transport, while air freight is around 190. A higher factor increases the chargeable kilograms per cubic metre, so the same pallet can incur different costs depending on the factor. Always confirm your specific factor rather than assume it is 250.

What that looks like

For example, a pallet measuring 1.2 metres long, 1.2 metres wide, and 1.4 metres high is about 2.02 cubic metres and holds 180 kilograms of goods.

With a 250 factor, the cubic weight is approximately 504 kilograms, so you are billed for 504 kilograms instead of 180. At 333, the chargeable weight is about 670 kilograms. With the 1000 factor, often used for Tasmania, it exceeds two tonnes for the same 180 kilograms of goods. The same pallet and contents can result in three very different charges.

How you pack also affects the chargeable weight. Reducing the pallet height from 1.4 metres to one metre by packing more densely or stacking efficiently lowers the cubic weight from 504 to 360 kilograms on a 250 factor. The same goods can result in a 144 kilogram reduction in chargeable weight through improved packing.

Getting the factor right for your freight

This is the most important consideration and relates more to your shipping arrangement than the calculation itself. The factor should match your freight profile, and should play a part in carrier selection. If your shipments are mostly dense, you should be charged based on actual weight at reasonable per-kilogram rates, and cubic weight should apply only to particularly bulky loads. Aim for a situation in which actual weight determines most pricing, with cubic weight as a secondary measure.

If you are consistently charged based on cubic weight, your freight may be bulky. It could benefit from improved packaging, or your current factor and rates might not correspond to your freight profile, resulting in unnecessary space charges. The latter is more common than many realise. It’s possible to discuss this with your carrier, and an established provider may be able to adjust the factor and rates to suit your shipping profile. To prepare, understand the proportion of your consignments that are charged by weight versus cubic weight, and on which routes.

Packing, and the number to watch

Whatever factor you are on, dimensions are a key price lever, often more significant than expected. A partly empty carton is charged for its full volume, so right-sizing packaging reduces costs. Pallet height and tight stacking directly affect the cubic measurement. Overhang can increase the overall footprint to the next size. It is important to declare dimensions accurately: if you understate them, a remeasure will correct it with an added fee; if you overstate them, you will overpay.

You do not need to become an expert in freight pricing. Instead, focus on one key number found on every invoice: the factor you are charged on, and whether your freight is priced by weight or space. Monitor this, keep your freight profile in mind, and pack accordingly to better control your shipping costs.