Courier Industry have complex way of weight calculation .There are various metrics of calculation .Broadly weight is calculated by measuring actual weight or volumetric weight whichever is higher is charged. 

Volumetric weight is calculated as mentioned below :- 

1. L (cm)*B(cm)*H(cm)/5000 - Mostly followed across world (Air Mode)

2. L(cm)*B(cm)*H(cm)/2700- Many MNCs follow this metric of calculation in India (Surface Mode)

3. L(cm)*B(cm)*H(cm)/ 27000*8- Many Indian logistics companies follow this 

1 inches =2.54 cm(Approx).

To avoid any weight discrepancy ,we request our customers to measure the dimensions properly and then pack it into as small box as possible . Polybag should be avoided ,or too much of space lying vacant in polybags attract volumetric calculation causing increased freight charges.