Freight Classifications Explained, a Guide to NMFC Codes

Shipping products across the country and around the globe requires a significant amount of administrative rigor. Correct documentation of products is one of the biggest pitfalls for ecommerce brands. There are so many terms to understand, it can be confusing and feel complex, even for domestic shipping only.  

Not only is it important to accurately label and document your products, but it can make a big difference in your overall transportation costs.  

Freight classifications may seem straightforward, but with new products coming to market all the time, there can be some subjectivity in assigning codes. Here’s everything you need to know as an ecommerce shipper to correctly classify your freight.  

What is Freight Class? 

Freight classification or freight class is a standardization of prices across all Less-Than-Truckload (LTL) freight carriers and businesses. This measurement is determined by National Motor Freight Traffic Association (NMFTA).  

Every commodity and product type is given a classification called a National Motor Freight Classification (NMFC), which corresponds to a specific freight class number. They range from 500 down to 50 and will always be based on the density of the product or material*. For example, bricks and cement are freight class 55, refrigerators are 92, and ping pong balls are class 500. Ping pong balls are very low density, therefore packing many into a freight container is lighter than packing the same volume of bricks.  

*Density is the main consideration when classifying freight—it’s the biggest factor, but as described below it’s not the only component. There are many aspects of classifying freight.  

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Types of Freight Classifications 

There are many factors in classifying freight. While density is the primary driver for which classification is used, there are other aspects to consider. The following are the most popular, but not the only factors.  

Freight Density 

The amount of space your freight takes up on a container or truck, relative to its actual weight, is the density of the shipment.  

Freight density is expressed as the ratio of weight-to-volume per cubic foot.  


Some products require special handling, which may move them into a higher freight class. Handling is determined by how difficult goods are to transport, as well as if they need special care. 

If freight is difficult to handle, it may be placed in a higher class. 


All freight considerations stem from how products fit into a shipping container or truck trailer. If items are odd or large sized, hazardous, fragile, or somehow difficult to stow, they require a higher freight classification.  

Storability (also called stowability) is based on a shipment’s size, shape, and ability to be stacked or nested. 


Some products may have a short shelf life. Medicine, food, and some other items are perishable or fragile items that need quick or careful transportation.  

The liability of products, like temperature-controlled or expedited shipping, can increase the freight class of an item.  


Like liability, the value of your products is a factor in classifying them. When shipping high value goods, the carrier takes on more responsibility than shipping low value goods.  

How much your products are worth is a freight class consideration. 

How Does Freight Class Affect Your Shipping Cost? 

It’s relatively simple to see that higher freight classifications are reserved for products that are more difficult for carriers to transport. Higher value, greater liability, and difficult stowability will all increase your freight class and increase the cost to ship your products.  

The lower your freight classification, the lower your price estimate for freight shipping cost. An item that is a class 60 will be cheaper to ship than an item classified at 400. 

While freight class is only a part of your overall transportation cost, it is a big factor, and it can mean your costs add up quickly. If your freight class is off, it can mean a huge cost difference.  

What are NMFC Codes? 

All commodities are also assigned an NMFC code, which is not to be confused with the freight class. NMFC codes further specify the materials being shipped.  

While freight class may be determined by some of the factors listed above, the NFMC code is assigned based on the specific type of commodity or raw material being transported. For example, computers and auto parts fall into the same freight class 250, but their NMFC code is totally different.  

NMFC codes specify the actual materials so that carriers can understand exactly what the contents of the shipment include.  

How to Avoid Increased Costs from Freight Classifications? 

It’s not frequent, but the NMFC does occasionally make changes to freight classification. Depending on the type or product you ship, these changes can have a big impact on your shipping costs.  

To ensure you are correctly classifying your shipments, you need to work with transportation experts to stay informed of any big changes.  

There are sometimes when you may need to adjust or revisit your freight class. For these it’s important to run a freight quote estimate first to see what the changes might mean for your transportation costs. If you work with a 3PL (third-party logistics) or other shipping provider, they will be able to run a freight cost estimate for you any time of year.  

Times when it’s helpful to run a freight cost estimate:   

  • Release a new version of your product 
  • Launch a new product  
  • Changing carriers or shipping services 
  • Moving inventory to a new fulfillment or warehouse location  
  • Launching your product in a new region 
  • Updating your packaging  



Need a freight quote? DCL’s transportation team has decades of experience getting customers the best service for reasonable prices. If you are seeking logistics or transportation support we’d love to hear from you. You can read DCL’s list of services to learn more, or check out the many companies we work with to ensure great logistics support. Send us a note to connect about how we can help your company grow.