What is Dimensional (DIM) Weight?

Dimensional Weight (or Volumetric Weight) is a pricing technique used by commercial freight transport companies, including USPS, FedEx, and UPS. It assumes that the cost of shipping a package should be based on the amount of space it takes up in a delivery truck, rather than strictly how much it weighs.

Why Do Carriers Use DIM Weight?

Imagine a delivery truck filled entirely with pillows. The truck is completely full by volume, but the actual weight is very light. If the carrier only charged by the pound, they would lose massive amounts of money because they could not fit any more packages inside.

To solve this, carriers calculate a "Dimensional Weight." You are always billed for the greater of the two numbers: Actual Scale Weight or Dimensional Weight.

The Cost of Shipping Air

If you ship a 2-pound pair of shoes in a massive 20x20x20 inch box, the Dimensional Weight is 57 pounds (based on a 139 divisor). You will be charged as if the box weighs 57 pounds. You are quite literally paying an exorbitant penalty for shipping empty air.

How to Calculate DIM Weight

• Formula: (Length × Width × Height) / DIM Divisor
• The most common domestic US DIM Divisor for UPS and FedEx is 139.
• Always round the final billable weight up to the next whole number. A package with a DIM weight of 4.1 lbs will be billed as 5 lbs.