When cargo is shipped by air, there is a generally accepted practice of the volumetric weight calculation. usually it is 167 kg per 1 cubic meter. Calculation of the volumetric weight of the package is made by the formula:

Length (cm) х width (cm) х height (cm): 6000

The largest of the actual and volumetric weights will be used as chargeable weight. 

Example: dimensions of the package (in cm): length - 140, width - 90, height - 100, actual weight of the package - 80 kg. Calculation of the volumetric weight will be done according to the formula:

140 x 90 x 100: 6000 = 210 kg

Volumetric weight is greater than actual, so chargeable weight will e 210 kg. 

The volume coefficient per one comic meter can vary, depending on the mode of transport:

167 kg  - air transportation by passenger aircraft (international, most used)

200 kg - Express delivery (FedEx)

200 -300 kg - air transportation by cargo planes (charters)

400 kg - some auto carriers.