Sometimes a parcel isn't very heavy but is still quite big. If this is this case, we work out the parcel's "volumetric weight". We calculate this by taking the volume of the parcel and dividing it by 5000 i.e.
Length x width x height
So if you have a 5kg parcel that is 100cm long, 35cm wide and 20cm high, the volumetric weight would be:
100 x 35 x 20