NMFC Classes Explained

Understanding your commodity will help you efficiently ship your freight through LTL carriers. NMFC number and freight classes are defined by the NMFTA (National Motor Freight Traffic Association) and made available through the NMFC (National Motor Freight Classification) on a quarterly basis. These NMFC numbers exist to provide a baseline for product standardization. 


An NMFC class, or NMFC Number, is used to classify and rate commodities based on a combination of 4 transportation characteristics, known as “SLED.” 

Stowability - This is determined by an item’s compatibility with other items on the trailer.  

Liability - This refers to the value of freight and the probability of it being damaged, stolen, or causing damage to other freight. 

Ease of Handling - The amount of care that this freight will need in order to be shipped. 

Density - Density is the pounds per cubic foot and refers to the measurable amount of space needed for an item. 

There are 18 classes that commodities are grouped into, ranging from a low of class 50 to a high of class 500. To give you a quick overview, a class 50 NMFC code generally refers to items that are lower in value, easy to handle and stow, and are quite dense. A Class 500 NMFC code, however, applies to commodities that are lower in density (such as ping pong balls) or extremely high in value. Based on the evaluation of the characteristics (density, handling, stowability, liability, and value), each commodity falls into a specific class code that identifies the type of freight being shipped. 


A Freight Class is typically used to classify shipments based only on their density. One of the most important things to note when identifying your freight’s NMFC Class is that it takes into account what the commodity is and its value. Due to this, Freight Class is not always the same as the NMFC Class. 


The NMFTA releases NMFC updates on a quarterly basis. 

Some carriers, including Roadrunner, offer a density calculator tool that will help shippers determine the approximate density and estimated class of your shipment. However, if you are looking for an exact classification, it is recommended to identify the NMFC code/number and ensure it is visible on the BOL used at the time of pickup.  

If you are still having trouble identifying your freight’s correct class, you can: 

  • Contact the manufacturer of your item, as they will be able to provide the NMFC codes for their products 
  • Call the National Motor Freight Traffic Association at 1.866.411.6632 
  • Reach out to your Roadrunner Account Executive for help