Australia Post uses Cubic weight calculations to measure the cubic weight of parcels for most contracts (such as eParcel or Startrack), or when using Own Packaging with MyPost Business.
They will typically charge the higher of cubic vs dead weight.
The cubic weight of a parcel is the parcel's volume in cubic metres, multiplied by 250. To work this out, use the formula below.
Examples
Height x length x width x 250 = cubic weight
For example: 0.5m X 0.3m X 0.4m
= 0.06m x 250
= 15kg cubic weight