Project Selfie examined load factors used in reporting by major airlines. It turns out that there is a wide range of ways the load factor is calculated by airlines. Weight alone yields low load factors (the percent of utilization of the aircraft with respect to cargo weight). Most of the airlines use a combination of weight and size, and this is done differently for different carriers. Thus they report load factors on different bases, so they are not comparable. IATA, the industry group, wants to have a more consistent basis than weight for reporting its figures for the industry. Weight alone is not very significant.
“(Weight alone) poorly reflects how full the planes really are.”
In short they cube out before they weigh out. Packages that go by air are not very dense! This may partially explain why air freight rates are going up while load factors are not very high. So IATA has been misrepresenting capacity utilization of planes.
Some notes on Project selfie: Weight loadfactors a poor way of showing utilisation, Project Selfie confirms – The Loadstar