Understanding Freight Class Categories

freight class categories

Any company that sources materials, manufactures goods or ships products to consumers must consider how they get those products into their customers' hands. More importantly, they must take into consideration the costs involved. 

One of the things that help determine shipping costs is the freight class that the products fall into. 

Getting your freight class right is critical. Get it wrong and you risk losing money, customers, and causing unnecessary shipping delays.

So, what are freight classes, and how are they categorized?


National Motor Freight Classification (NMFC)

To help shippers determine their freight class categories when getting ready to ship their goods, the National Mode of Freight Traffic Association (NMFTA) sets the standard for how they are determined. These classes are then made available to all supply chains via the National Motor Freight Classification (NMFC).

In fact, all carriers should be able to provide a chart of these freight classes upon request.

Currently, there are a total of 18 Types of freight classes, each with their own subgroups. 

When the NMFC compile these freight classes they give each class a unique code. Each of the 18 freight classes gets assigned a number ranging between 50 – 500.

This is the commodity number. It is this number that shippers place on the BOL so as to allow the carrier to easily identify what the package contains. Essentially, this number helps expedite the classification process and in-turn, the shipping speed.

Furthermore, the numbers are associated with 1 of 4 categories…


The NMFC Commodity Number Categories

A list of these freight class categories can also be found on the NMFTA Website. And most of the time, carriers supply their clients with this information, usually upon request. 



Density, with its groups and sub-groups, indicates that the goods fall into a density-based class. This is clarified in the NMFC table. 

If you ever need to ship via a density-based class, it is actually fairly simple to calculate the cost. 

First, we take the measured weight of the item in pounds and the physical volume (length x height x width)  measured in inches. We then divide that number by 1728. This result divided into the weight of the item (expressed in pounds) provides the "pounds per cubic foot" or PCF value.

It sounds more complicated than it actually is!



In general, most items are stowable. These items are ones which stow well in trucks, trains, or boats. This category considers the actual shape and stability of the goods versus their density.

This category indicates to the carrier that the goods are easily stackable, contains no protruding parts, and are too large for more standard shipping modes.



Some items only require standard carrying procedures. But some, due to weight, shape, fragility or hazardous properties require special handling. 

Classification of special treatment represents the difficulty in loading or carrying the item(s) which if applicable, again will incur extra handling costs.



This category indicates more precious items that may be susceptible to freight theft or might damage adjacent freight during transport. 

Perishable cargo, freight prone to tip,  spontaneous combustion or explosion is also classified based on liability and assigned a value per pound of goods transported. This is usually just a fraction of the liability of the carrier. 


Final Thoughts

Without this knowledge, shippers run the risk of overpaying or even overestimating costs based on the wrong classifications.

Want to learn more about freight classes affect your business? Reach out to the logistics professionals here at Redwood Logistics!