Amazon Seller Guide: What is dimensional weight

Shipping companies or courier service providers have always, until recently, used package weight as the common denominator to calculating the costs in which customers have to pay for their services. Within the past 10 years, this has now changed and courier service providers have now shifted to use Dimensional Weight. But what is it?

Dimensional weight or volumetric weight is a technique to calculate the shipping cost for commercial freight transport. It is mainly used by postal and courier service providers to consider both weight and volume of the packaging to determine appropriate shipping cost. 


  • Dimension: Width, Height, Length measurements( of a package)
  • Volumetric: relating to the measurement of volume
  • Volume: the amount of space that a substance or object occupies, or that is enclosed within a container
    Calculated by Weight x Height x Length measured in cubic centimeters or inches

To calculate the dimensional weight, you need to know the DIM Factor (dimensional weight factor). The DIM Factor is the allowed volume per unit weight. Therefore, it is expressed in cubic inches/lbs. or cubic feet/lbs. or as cubic meters/kg. To put easily the “weight limit for the specific package size”

Calculate the dimensional weight of your package by dividing its volume by DIM factor.

Dim factor: The factor that represents cubic inches per pound.

IATA ( The International Air Transport Association ) DIM Factors

Currently used by most large North American couriers:
Domestic = Dim Factor [in3/lb] = 166 ; [cm3/kg] =6000
International = Dim Factor [in3/lb] = 139 ; [cm3/kg] =5000

Most US shipping companies use the imperial system (pound, inch, etc) whereas the rest of the world uses the metric system (kilogram, centimeter). The DIM factor also varies according to domestic or international shipment.

So for example if we were to use the IATA DIM Factor for an international package going from Thailand to USA being the package is

10(Width)X 14(Length)X 12 (Height)/ 139 = 12.0 lb is the dimensional weight

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