What Is Freight Class and NMFC in Trucking?
Also called: NMFC Code, NMFC Class, National Motor Freight Classification
Freight class is a number from 50 to 500 that LTL carriers use to price a shipment, based on the kind of goods. It comes from the National Motor Freight Classification, or NMFC, which NMFTA keeps. In 2025 density became the main factor, but handling, stowability and liability can still change a class. Carriers expect the NMFC item number and the class on the bill of lading.
Last reviewed September 23, 2026 · Facts checked October 16, 2026
Key Points
- Freight class numbers run from 50 to 500. Class 50 is the densest freight and class 500 is the least dense (NMFTA)
- The NMFC is a classification system for LTL freight. NMFTA calls it a voluntary standard, and the standard to use when no carrier tariff says otherwise
- Four things decide a class: density, handling, stowability and liability (NMFTA)
- Density is pounds per cubic foot. In 2025 NMFTA made density the main factor. For example, freight of 50 pounds per cubic foot or more is class 50
- An NMFC item number identifies the commodity. It is five or six digits. A freight class is the price tier that goes with it. They are not the same thing
- A carrier can inspect and re-class a shipment, then bill the difference. Check the carrier's rules before you ship
- Freight class has nothing to do with hazardous materials class
What is freight class?
Freight class is a number that tells an LTL carrier how to price a shipment. NMFTA defines it as the number assigned to an article, or group of articles, to work out the applicable rate. Classes run from 50 to 500. A lower class means denser, easier freight and generally a lower rate. A higher class means lighter, bulkier or more fragile freight and generally a higher rate. The class is used for less-than-truckload freight. Full truckloads are not priced this way.
Are freight class and NMFC code the same?
No, but they go together. The NMFC is the whole classification system. An NMFC item number is a five or six digit code for a specific commodity, such as an item for frames or tools. Each item has a class, or a class that depends on density. So the item number says what the goods are, and the class says which price tier they fall in. A shipper usually puts both on the bill of lading. The NMFTA says the NMFC is a voluntary standard, but LTL carriers still need the class to price a shipment.
How is freight class determined?
NMFTA says four things decide a class: density, handling, stowability and liability. Density is how much the shipment weighs for the space it takes up, in pounds per cubic foot. Handling means how hard the goods are to load and move. Stowability covers whether the goods can share a trailer with other freight. Liability covers how likely the goods are to be damaged or stolen. In 2025, NMFTA made density the main factor. It expanded its density scale to 13 bands. For example, 50 pounds per cubic foot or more is class 50, 35 to under 50 is class 55, and 30 to under 35 is class 60. Goods with handling, stowability or liability concerns still have to use the right item number.
How do you find your NMFC code?
Look up the commodity in the NMFC, which NMFTA offers through its ClassIT+ tool. Many carriers and 3PLs also help shippers find the item. If you cannot find it, NMFTA says classification assistance and interpretation requests go through the NMFTA Store. Measure the shipment as it will be tendered, including the pallet. Our freight class calculator can estimate the class from the weight and dimensions. Treat that as a starting point and confirm it with the carrier.
What happens if you use the wrong class?
The carrier can inspect, reweigh and re-measure the shipment. If the class is wrong, it can re-class the freight and bill you the difference, and sometimes an extra fee. Rules vary by carrier, so read the carrier's tariff and rules. The best protection is to measure carefully, use the right item number and keep records, such as the weights and photos, that back up your class.
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Frequently Asked Questions
What is an NMFC code?+
An NMFC item number is a five or six digit code for a specific commodity in the National Motor Freight Classification. Each item has a freight class, or a class that depends on density. LTL carriers use it to price a shipment.
Are freight class and NMFC the same?+
No. The NMFC is the classification system. The item number says what the goods are. The freight class is the price tier, from 50 to 500, that goes with them.
How is freight class determined?+
NMFTA says density, handling, stowability and liability decide a class. In 2025 density became the main factor. Density is the weight of the shipment divided by the space it takes up, in pounds per cubic foot.
How many freight classes are there?+
Freight classes run from 50 to 500, with 50 for the densest freight and 500 for the least dense, according to NMFTA. Common classes in between include 55, 60, 65, 70, 85, 100, 125, 150, 175, 200, 250, 300 and 400.
Are NMFC codes required?+
NMFTA calls the NMFC a voluntary standard, but it is the standard to use when no carrier tariff says otherwise. In practice, LTL carriers need the class to price a shipment, so you will be asked for it.
Is freight class the same as hazmat class?+
No. Freight class is a pricing tier for LTL freight. Hazard class is a safety category for hazardous materials. They are separate systems, and a shipment can have both.
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This is industry terminology and typical practice. It is not legal or tax advice. Rates, fees, and rules mentioned are general ranges. Confirm the details on your rate confirmation, carrier agreement, or a current official source.