Cubic or Dead Weight?

When sending a parcel with a courier, it is important to understand the difference between an item’s cubic and dead weight. Dead weight is simply the mass of the parcel (including all packaging materials) as measured by a set of scales.

Cubic weight is slightly more complicated and is calculated by multiplying the external dimensions of the parcel (in centimetres), then dividing by a cubic divisor (typically 4000 for domestic and 5000 for international). This is best illustrated with an example:

John wants to send several items interstate in a large box with dimensions 1m x 50cm x 40cm, weighing a total of 30kg. The cubic weight of this parcel is (100cm x 50cm x 40cm) / 4000 = 50kg.

In this case, the cost to send John’s parcel is based on its cubic weight of 50kg, significantly more than its 30kg dead weight.

This is why it pays to pack items tightly and minimise empty space. This practice also protects items more effectively as they will not move around in transport.