The actual volume and weight will be combined together to find the volumetric weight. So a package that is lightweight but very large could cost much more than its actual weigh.

If you have a package that is 100 cm x 100 c,m x 50 cm and weighs only 15 kilos, the volumetric weight would be 50 kilos. Calculated by: (100 cm x 100 cm x 50 cm) / 5,000 = 50 kilos