Volumetric or Dimensional weight is used by Couriers to calculate a minimum weight for a parcel of a given size. The reason for this is that a large but very light package will still take up a lot of space, so the couriers will need to charge by size instead of weight. Normally the volumetric weight is calculated and then the greater of the volumetric weight and the actual weight is used.
To calculate the volumetric weight, the volume of the package being sent is measured then divided by a shipping factor. The exact factor will depend on the courier, the units used, the destination of the parcel and the method of transport (e.g. road/air). Further details can be found on the Courier’s documentation and our Courier-specific pages
As an example:
Interlink Air shipments use a Shipping Factor of 5,000 when cm and kg are used.
Multiply the length x height x width in centimetres and divide the answer by the shipping factor of 5,000.
Let’s say you have a parcel that weighs 8kg. It measures 40cm x 30cm x 50cm. That gives a volume of 60, 000 cm3.
Dividing by 5,000 gives a volumetric weight of 12kg.
This is higher than the actual weight, so the volumetric weight is used for shipping calculations.