You can save money on Australia Post shipments with use because you only pay by the physical weight.
Length: 31cm (0.31m)
Width: 15cm (0.15m)
Height: 16cm (0.16m)
(L) 0.31m x (W) 0.15m x (H) 0.16m
Physical weight: 0.9kg
Cubic weight: 0.00744m3 x 250*
*Cubic via Australia Post is measured by a factor of 250.