What are Dimensional Weight Charges (Dim Weight)?

Dimensional weight, also known as volumetric weight, is a pricing technique for commercial freight transport (including courier and postal services), which uses an estimated weight that is calculated from the length, width and height of a package.

Shipping costs have historically been calculated on the basis of gross weight in kilograms or pounds. Lightweight, low-density packages become unprofitable for freight carriers due to the amount of space they take up in the truck/aircraft/ship in proportion to their actual weight. The concept of dimensional weight has been adopted by the transportation industry worldwide as a uniform means of establishing a minimum charge for the cubic space a package occupies.