NMFC Freight Class
Freight class is an 18-level standard used in US less-than-truckload shipping, running from class 50 for the densest cargo to class 500 for the lightest.
Definition
Published by the National Motor Freight Traffic Association, the classification is primarily driven by density in pounds per cubic foot, with higher class numbers attracting higher rates per pound.
Density is the starting point but not the final answer. The NMFC also weighs stowability, handling difficulty, liability and value, which is why a carrier can reclassify a shipment after inspection.
Formula
Density = total weight (lb) ÷ total volume (ft³)
Example
A pallet weighing 800 lb and occupying 44.44 ft³ has a density of 18 lb/ft³, which falls into class 70.
When you will come across it
- Booking LTL freight within the United States
- Checking whether a carrier's reclassification of your shipment was justified
- Designing packaging so the product falls into a cheaper class
Frequently asked questions
What density gives me the cheapest class?
Class 50 applies to cargo with a density of 50 lb per cubic foot or greater, and it is the cheapest class to ship.
Can a carrier change my freight class after booking?
Yes. If the actual shipment differs from the description on the bill of lading, the carrier can reclassify it and bill the difference, so measure accurately.
Is freight class used outside the United States?
The NMFC classification is a US domestic standard. International shipments use volumetric weight and weight-or-measure conventions instead.