Wondering what freight classes are and how they impact your shipping costs? These standardized categories—18 in total—play a key role in determining how much you’ll pay for transporting goods. If you’re shipping via less than truckload (LTL), understanding freight classification is essential for keeping your costs under control.
Freight class reflects how “transportable” a product is, based on four main factors: density, ease of handling, liability, and stowability. In the U.S., each type of commodity receives a National Motor Freight Classification (NMFC) code, which standardizes pricing across carriers.
The system ranges from Class 55 (dense items over 50 lb per cubic foot, usually the cheapest to ship) up to Class 500(light items under 1 lb per cubic foot, typically the most expensive). In short, the lower the class number, the lower the freight charge.
In this guide, we’ll walk you through how freight classifications work—so you can make smarter shipping decisions and avoid unnecessary expenses.
What Is Freight Class and Why It Matters
Freight class is a standardized system created by the National Motor Freight Traffic Association (NMFTA) to categorize shipments based on how easily and efficiently they can be transported. Unlike Full Truckload (FTL) shipping—where cost is typically based on weight alone—freight class adds more nuance to pricing in Less Than Truckload (LTL) shipping.
This classification relies on four key factors:
- Density: The ratio of weight to volume. Denser items are more space-efficient and usually fall into lower (cheaper) classes.
- Liability: The risk involved in shipping an item, including potential for theft, damage, or hazard to other goods.
- Stowability: How well the freight fits with other cargo in the truck, considering shape, packaging, and restrictions.
- Handling: How easy the shipment is to move, load, and unload.
So, why does freight class matter?
- It creates industry-wide consistency—ensuring everyone from shippers to carriers speaks the same “classification language.”
- It directly impacts shipping costs, since pricing is based not just on weight, but also on how difficult a shipment is to transport.
Getting your freight class right from the start prevents costly surprises, like reclassification fees or damaged relationships with carriers.
How Freight Class Is Calculated
Freight class is determined based on four main characteristics of your shipment. Although all four factors matter, density typically carries the most weight when assigning a class.
How to Calculate Freight Density
Follow these steps to determine your shipment’s density—the key factor in classification:
- Measure the dimensions of your shipment in inches (length × width × height)
- Convert to cubic feet: divide the result by 1,728 (the number of cubic inches in a cubic foot)
- Divide the total weight (in pounds) by the cubic feet to get the density
- Compare your result to the NMFC freight class chart
Example:
A shipment measuring 48″ × 40″ × 60″ and weighing 500 lbs would be calculated as follows:
- Volume: (48 × 40 × 60) ÷ 1,728 = 66.67 cubic feet
- Density: 500 ÷ 66.67 = 7.5 lbs per cubic foot
- Estimated class: 125
Additional Factors That May Affect Freight Class
While density is central, the following factors can also influence your final classification:
- Handling: Does the shipment require special equipment or care during loading/unloading?
- Stowability: Can the freight be safely and efficiently placed with other cargo?
- Liability: Is the shipment fragile, valuable, or hazardous?
Getting the freight class right is critical—it prevents costly reclassification fees and ensures your goods are handled properly during transit.
Many carriers now offer online density calculators to help you determine the correct freight class quickly and accurately.
Understanding the 18 Freight Classes
The 18 freight classes provide a structured framework across the LTL shipping industry, with classifications ranging from Class 50 to Class 500. Each class corresponds to specific density ranges and shipping challenges.
See the table below for a complete overview of all 18 freight classes, including typical density ranges and product examples.
| Freight Class | Density (lbs/ft³) | Typical Commodities |
| Class 50 | ≥ 50 | Bricks, cement, steel rods |
| Class 55 | 35-50 | Heavy metal parts, castings |
| Class 60 | 30-35 | Steel cabinets, metal furniture |
| Class 65 | 22.5-30 | Engines, large tools |
| Class 70 | 15-22.5 | Auto parts, food products |
| Class 77.5 | 13.5-15 | Paper goods, consumer electronics |
| Class 85 | 12-13.5 | Office furniture, textiles |
| Class 92.5 | 10.5-12 | Carpets, furniture kits |
| Class 100 | 9-10.5 | Machinery, household items |
| Class 110 | 8-9 | Plastics, rolled flooring |
| Class 125 | 7-8 | Small appliances, lighting fixtures |
| Class 150 | 6-7 | Bicycles, assembled furniture |
| Class 175 | 5-6 | Wood chairs, plastic containers |
| Class 200 | 4-5 | Cabinets, toys, assembled equipment |
| Class 250 | 3-4 | Mattresses, upholstered furniture |
| Class 300 | 2-3 | Wood tables, model boats |
| Class 400 | 1-2 | Lightweight displays, foam items |
| Class 500 | <1 | Ping pong balls, gold dust, very bulky/light items |
Importantly, lower class numbers directly translate to lower shipping costs, as these items are easier and more efficient to transport. When shipping mixed items on the same pallet, carriers typically apply the highest class among those items. For instance, shipping car accessories (Class 60) with car covers (Class 100) results in the entire pallet being classified as Class 100.
Misclassification frequently leads to reclassification by carriers, resulting in unexpected fees that can range from minor increases to several hundred dollars, depending on the severity of the error. Consequently, accurate classification isn’t just a best practice—it’s essential for controlling shipping costs and maintaining strong relationships with carriers.
Conclusion
Understanding freight classes is essential for controlling shipping costs and avoiding unexpected reclassification fees. The system of 18 classes—from 50 to 500—standardizes LTL pricing based on density, handling, stowability, and liability. By accurately classifying your freight and strategically organizing mixed shipments, you can reduce expenses, improve negotiations with carriers, and streamline your shipping operations.
Sources:
- https://www.easycargo3d.com/en/try-container-loading-calculator-online-for-free/
- https://www.fmlfreight.com/freight-101/freight-classes/
- https://www.cdlogistics.ca/freight-news/what-are-freight-classes/
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