What is Freight Class?

Freight class is a standard classification system for shipments, defined by the National Motor Freight Traffic Association (NMFTA). It's used to categorize commodities like Filters for transport, taking into account factors like weight, dimensions, density, storage capability, ease of handling, and liability. Freight class is a system to categorize different types of goods being shipped.

How to determine Freight Class

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Density is a key concept in freight shipping, as it significantly impacts the freight class for commodities like Filters and hence, the shipping cost. It is calculated as the weight of the shipment divided by its volume. It's a calculation of how much a shipment weighs compared to its volume.

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Stowability is used in freight shipping to describe how easily an item can be stowed or stored in relation to other items. For example, when trying to understand stowability for Filters, it is important to know if the item can be packaged efficiently and stowed onto the truck easily. In other words- Stowability is how easily a shipment can be loaded and stored for transport.

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Liability is a term used to refer to the accountability or risk involved in transporting Filters. It's one of the factors considered when determining freight class. Liability is the degree of financial risk assumed in the transportation of goods.

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Handling refers to the procedures and precautions taken when moving and storing Filters. It is one of the factors considered when determining freight class for Filters. Handling refers to the procedures involved in safely moving goods.

Freight Class Commodities


Air Filter Padding



Water Filter Tanks





NOI, in boxes. Outer shipping containers may be printed or labeled with shipper's name and address but not printed or labeled with advertising or with uncoded information as to the nature, identity, model or caliber of the articles contained therein. Packing lists affixed to the outside of shipping container must be enclosed in a sealed, opaque envelope or pouch.

Common Commodity Items



For many NMFC® codes there isn’t just one single class that is applied. Often, NMFC® numbers have multiple "sub-classes", which are almost always based on the density of the shipment. In the instance where your NMFC® number has multiple sub classes, it's best to contact an expert, like Koho, to help identify which subclass to use.


Do all LTL shippers use NMFC freight classes?

Almost all U.S. LTL carriers use NMFC freight classes, although some are attempting to move to a dimensionally-based system.

What is a CWT rate?

CWT stands for hundredweight. LTL shipments are priced “per 100 pounds,” “cwt,” or “per hundredweight.” This means that a 400 lb shipment priced at $25 CWT would cost $100, not including accessories or specialty services.