Freight Class

Freight class is an important measurement system used by carriers for pricing and formulating the cost to ship your freight. Whether you want to look up NMFC classification or calculate freight density, FreightCenter offers tools and experts to assist you in determining the freight class of your shipment.

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What is freight class and how is it determined?

Freight class is a standardized pricing system for commodities transported via less-than-truckload (LTL) freight shipping. The pricing system ensures that customers receive a fair price when shipping freight.

Freight class is assigned to a shipment based on either the specific commodity being transported or the total density of the freight being shipped.


To understand freight class, you first need to know about National Motor Freight Classification® (NMFC). NMFC is a classification system created and maintained by the Nation Motor Freight Traffic Association (NMFTA), a nonprofit membership organization of motor carriers.

NFMC codes are assigned a freight class (or category) by the NMFTA based on certain qualifications. Almost every item you can think of – from airplane parts to zippers – is given an NMFC code (or number) by the NMFTA.

FreightCenter uses the acronym SLED to abbreviate the four transportation characteristics which determine freight class:

  • Stow-ability – Stow-ability takes into account how your freight can be transported with other commodities. Freight that is flammable, perishable, or hazardous is regulated and can’t be shipped with certain materials. When thinking about stow-ability, consider how your freight is packaged. Items that are crated or boxed are usually stackable and easier to pack inside a cargo container or truck.
  • Liability – Liability refers to the value of a commodity, the likelihood of theft or damage, and the probability of the item causing damage to other freight during shipping. Possessing a greater risk will result in a higher freight class.
  • Ease of handling – When classifying freight, the level of care needed during shipping is taken into consideration. If the item is fragile, requires special attention, or has hazardous properties it will fit into a higher class and increase shipping cost. Size, weight, and shape also contribute to freight class.
  • Density – Density, or pounds per cubic foot, is the measurable amount of space needed for an item. Commodities that are compact and have a higher density fall into a lower class and are cheaper to ship than bulky items. Use our Density Calculator to find the density of your freight.

The freight class of the items you are transporting is a major factor in determining the cost of your freight shipment. There are 18 freight classes – ranging from 50 (the least expensive) to 500 (the most expensive). Items that are high in density (heavy and compact) and less susceptible to damage are given a lower freight class. Items that are low in density and more susceptible to damage are given a higher freight class.

Examples of items with specific freight classes include:

  • Palletized Bricks – 50
  • Generator – 70
  • Baseballs – 85
  • Gong – 77.5
  • Radios – 125
  • Thermometers – 150
  • Bamboo Furniture – 250
  • Gumball Machine – 300
  • Ping Pong Ball – 500

You can use our freight class lookup tool to view the freight class of other commonly shipped items.


Density is used for shipping objects that vary in size or when the number of items shipped varies from shipment to shipment. For example, commodities such wooden tables and clothing are classified simply by density. Wooden tables are considered density-based because there is not one standard size for tables. The shipper could be shipping small coffee tables or large dining room tables; therefore, it is more accurate to use density. Clothing is shipped using density because the shipper could be transporting 500 pounds or a ton. These types of shipment are based on density because the NMFC code is not enough to determine the class.

There are some items that are not classified by an NMFC number at all. These items fall into a general category referred to as Not Otherwise Indicated (NOI). In these special cases, the freight class is based on density.

If your product has a density-based freight class or is considered NOI, you can use our density calculator to estimate its freight class.


Our Density Calculator uses your shipment’s length, width, height, and weight to determine its density. The calculator then recommends a freight class based on that number.

For example, a shipment that works out to 1.31 PCF and weighs 100 pounds (Class 300) will be much more expensive to ship than an item that has the same weight but equates to 9.67 pounds per cubic foot (Class 100). In other words, the more space your freight occupies on a truck or in a container, the more costs you will incur for transport.

Freight Density Freight Class
Less than 1 400
1 but less than 2   300
2 but less than 4 250
4 but less than 6    175
6 but less than 8 125
8 but less than 10 100
10 but less than 12 92.5
12 but less than 15 85
15 but less than 22.5 70
22.5 but less than 30 65
Over 30 60

Why knowing your freight class is important

Freight Class is an important factor used by carriers to categorize freight for pricing purposes. If you know your cargo's NMFC number or can provide accurate weights and dimensions when calculating its density, you will be able to determine the freight class which most best represents your freight. When a carrier is provided with accurate freight class and dimensions, the carrier is less likely to re-class a shipment. To the shipper, this means you are more likely to avoid billing adjustments and higher shipping charges.

If you aren’t sure your freight shipment’s freight class, follow these steps:


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