NMFC stands for National Motor Freight Classification. It is the standard that LTL carriers in the United States use to group freight by how hard it is to move. Every type of commodity has an NMFC item number, and every shipment has a freight class from 50 to 500. The class is one of the main things that decides the price.
The standard is published by the National Motor Freight Traffic Association (NMFTA). If you ship or broker LTL freight, the NMFC is why two pallets of the same weight can cost very different amounts.
NMFC number and freight class: the difference
They are related, but they are not the same thing.
NMFC item number | Freight class | |
|---|---|---|
What it is | A code for a type of commodity | A rating of how costly the freight is to carry |
Looks like | A five- or six-digit number, sometimes with a sub-number | One of 18 values from 50 to 500 |
Where it appears | On the bill of lading, next to the description | On the bill of lading and the carrier's rating |
What it does | Tells the carrier what the freight is and which rules apply | Sets the rate, together with weight and distance |
The item number identifies the goods. The class prices them. One item number can lead to several classes, depending on the density or packaging of the shipment.
The 18 freight classes
Classes run 50, 55, 60, 65, 70, 77.5, 85, 92.5, 100, 110, 125, 150, 175, 200, 250, 300, 400 and 500.
Low classes are dense, sturdy freight that is easy to handle, such as bricks or steel parts on a pallet. High classes are light, bulky or fragile freight, such as assembled furniture or ping-pong balls. The higher the class, the higher the rate per hundred pounds.
How class is decided
Four characteristics define how freight is classed:
Density. Weight divided by the space the shipment takes up, in pounds per cubic foot.
Handling. Whether the freight needs special care or equipment to move.
Stowability. Whether it can be loaded with other freight. Odd shapes, hazardous goods and items that cannot be stacked score worse.
Liability. The value of the freight and how likely it is to be damaged, stolen or to damage other freight.
What changed in 2025
In July 2025 the NMFTA reworked the classification. Most freight that has no special handling, stowability or liability issues is now classed by density alone, on a standard 13-tier scale. Commodities that do have those issues keep their own rules.
In practice, the dimensions and weight you put on the bill of lading matter more than before. For most shipments, accurate measurements decide the class.
How to find the class for a shipment
Measure the shipment as it will ship. The longest, widest and tallest points, including the pallet and packaging.
Weigh it, pallet included.
Work out the density. Cubic feet are length times width times height in inches, divided by 1,728. Density is weight divided by cubic feet.
Match the density to a class.
Our free freight class calculator does steps three and four and shows the full density scale. To see how much trailer floor the shipment takes, use the linear feet calculator.
For the item number and any commodity-specific rule, the official source is ClassIT, the NMFTA's lookup tool. It is a paid subscription. Carriers and many brokers have access and can confirm the code.
Why getting it wrong is expensive
LTL carriers inspect freight at their terminals. If the weight, dimensions or description do not match the bill of lading, the carrier corrects them and re-rates the shipment. You receive:
A higher freight charge based on the corrected class or weight.
An inspection or reclassification fee on top.
A billing dispute that takes time to resolve, often after the customer has already been invoiced.
For a broker, that difference usually comes out of the margin. The fixes are simple: measure rather than estimate, include the pallet, describe the freight accurately, and keep photos and the packing details in case of a dispute.
When NMFC does not apply
Freight class is used for LTL. A full truckload shipment is priced for the truck, usually per mile, so it does not need a class. Parcel carriers use their own dimensional weight rules.
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