Demystifying Density-Based Freight Class
Freight Class vs NMFC: Everything You Need To Know About NMFC Classification
When you schedule a shipment without first determining the proper NMFC classification, there's a good chance your shipping quote won't match your final invoice. By taking time to understand some transportation characteristics and the freight classification system, you'll be able to classify your freight correctly and avoid potentially costly surprises down the road.
We've answered several key questions about NMFC numbers, or codes, and freight class to ensure you're properly classifying your shipment:
The National Motor Freight Classification (NMFC) is the standard set of numbers/codes established and managed by the National Motor Freight Traffic Association (NMFTA) that help determine which resulting freight class your shipment will fall under. NMFC item numbers are based on the shipment commodity that can be found on the NMFC website.
The short answer? No. Although the terms are related and are frequently used interchangeably, the two shipping terms are not the same. Each LTL shipment in the United States, Canada and Mexico is assigned an NMFC code and a resulting freight class. Freight class is the system used by the industry to categorize commodities, which helps shippers and carriers standardize shipments and costs based on certain shipping characteristics. While freight class represents a finite number of broad commodity categories, NMFC codes represent more specific subcategories within freight classifications for further identification.
Your shipment is assigned an NMFC code aligned with one of 18 possible freight classes (Class 50 to Class 500). The NMFC code is based on the commodity the shipment contains, and then the shipment's freight class is determined based on four shipment characteristics: density, stowability, handling and liability. Freight classes can sometimes change, so be sure to keep current on both NMFC class and codes.
The shipment's freight class is dictated by its commodity type and 4 shipping characteristics:
- Density — each commodity has its own shipping density, so its dimensions in relation to its weight affects the optimal "fill" of an LTL trailer.
- Stowability — Freight that is large, heavy, or hazardous affects the complexity of the load.
- Handling — Freight that requires special handling, like additional manpower, can affect pricing.
- Liability — Items with increased liability, such as higher valued or perishable items, may dictate a higher class.
No. NMFC numbers are only used in the United States, Canada and Mexico.
Once you know the correct NMFC code and class for your shipment, you can complete your quote request and BOL. Knowing the proper class ensures your quote from the carrier is accurate — plus, it helps you avoid reclassification and billing surprises.
Commodities have a wide density range. In some cases your item may be assigned a density-based classification, meaning the ratio of the item's weight by its dimensions will influence the total shipping cost. Typically, the lower the density, the higher — and more expensive — the freight class will be.
To determine the accurate density of your shipment, measure its dimensions in inches and round to the nearest inch. You'll also have to weigh your shipment — including its packaging — with an accurate shipping scale. You can then use Unishippers' freight density calculator to easily discover the density of your shipment.
Carrier pricing for LTL shipping varies, so it is important to know which method your chosen carrier employs as the difference can be significant to your bottom line. Two of the most common methods are:
- NMFC class code pricing (more common) — The carrier assigns rates based on the shipment's freight class. The reasoning is that higher density items take up less space on the truck and are less prone to damage.
- Freight density pricing — The carrier rate is based on the LTL shipment's density: the occupied space on the truck in relationship to its weight. In this method a freight density calculator is used to determine the shipment's dimensional (DIM) weight.
Have more questions about freight classification? Watch our NMFC class and code instructional video or contact our Unishippers team of experts for help determining the appropriate class for your freight shipments.