Dimensional Weight Explained: How Volumetric Weight Works

What is dimensional weight?

Dimensional weight converts package volume into an equivalent weight value using a divisor or conversion factor specified by the carrier or freight service.

Why dimensional weight exists

A large lightweight package can occupy substantial vehicle or aircraft space even though its actual weight is low. Dimensional-weight methods allow freight pricing to account for both space and mass.

Actual weight vs dimensional weight

Actual weight is measured on a scale. Dimensional weight is calculated from package dimensions. Depending on the service rules, the higher applicable value may be used as the chargeable weight.

Why the divisor matters

There is no single universal dimensional divisor for every carrier, service, route or unit system. The divisor used by the applicable carrier or tariff should be confirmed before calculating a final chargeable weight.

Measure the package correctly

• Measure the outer dimensions of the packed shipment.
• Use the unit system required by the carrier formula.
• Account for protrusions or packaging that increases external dimensions.
• Follow the carrier's stated rounding rules where applicable.

Example calculation structure

Suppose a carrier formula uses length, width and height in centimeters. First multiply those three dimensions to obtain package volume, then divide by that carrier's specified divisor.

How packaging can affect dimensional weight

Oversized packaging increases package volume. Reducing unnecessary empty space can therefore reduce dimensional weight in situations where dimensional pricing applies.