A shipping class is a standardized numerical designator used by carriers to determine the price for transporting Less-Than-Truckload (LTL) freight. This system measures how difficult and expensive a commodity is to ship. By assigning a class number, carriers uniformly assess the space a shipment occupies, the risk it carries, and the effort required to handle it. This classification directly influences the rate a shipper pays, making accurate determination necessary for predictable budgeting.
The Foundation of LTL Freight Pricing
The freight classification system provides a standardized language to compare the thousands of different commodities shipped daily. This standard is the National Motor Freight Classification (NMFC) system, governed by the National Motor Freight Traffic Association (NMFTA). The NMFC system allows carriers to assess the cost and risk associated with moving goods in a shared-trailer environment. This standardized classification ensures fair pricing by comparing the “transportability” across various products. The freight class system is almost exclusively relevant to LTL shipments, which combine freight from multiple shippers into one trailer.
The Four Determinants of Freight Class
The NMFC system rests on four distinct characteristics that describe a commodity’s transportability. These four factors are used in combination to assign the numerical class. Some commodities have a fixed classification, while others are variable and density-based. Understanding how these elements interact is necessary for determining the correct freight class and ensuring accurate pricing.
Density
Density is the single most influential factor in determining freight class, representing the weight of a shipment in relation to the space it occupies. It is measured in pounds per cubic foot and relates directly to a carrier’s ability to maximize trailer capacity. Compact and heavy commodities, such as machinery or bricks, are considered high-density freight and are desirable to carriers. Low-density items, like ping-pong balls, take up significant space without adding much weight, leading to a higher, more expensive freight class.
Stowability
Stowability refers to how easily a commodity can be loaded and transported safely with other items in the same trailer. While most freight is expected to stack neatly, items with irregular shapes, excessive length, or those that cannot be stacked are considered poorly stowable. Hazardous materials are restricted from being loaded near certain other goods, which reduces the carrier’s flexibility and results in a higher freight class.
Handling
Handling measures the difficulty or special care required to load, unload, and move a shipment throughout the LTL network. Fragile, perishable, or oddly shaped items often require special equipment or additional labor, increasing the carrier’s operational costs and risk of damage. Freight requiring special attention, such as large glass sheets, is assigned a higher class because it demands more careful and time-consuming processes than standard palletized goods.
Liability
Liability addresses the risk associated with transporting the item, focusing on the potential for theft, damage, or the possibility of the item damaging other freight. High-value commodities, such as electronics, carry a higher liability risk for theft and require additional security measures. Items prone to spoilage, combustion, or leakage will also increase the class because they pose a risk to the carrier and the surrounding cargo.
Understanding the 18 Freight Classifications
The NMFC system uses a scale of 18 classifications, ranging from Class 50 to Class 500, to categorize all commodities. This scale establishes an inverse relationship between the class number and the density of the freight. A lower class number indicates a lower cost and a higher density, meaning the item is efficient to transport because it is heavy for its size.
Class 50, often called “clean freight,” is the least expensive to ship and is reserved for very dense, durable items like palletized cement or steel bolts. Classifications like Class 100 are assigned to mid-range density items such as parts and machinery. The most expensive freight falls into the highest range, such as Class 500, which is reserved for extremely low-density, high-volume items like bags of ping-pong balls.
Calculating Your Shipment’s Freight Class
For commodities without a fixed classification, determining the correct class begins with an accurate density calculation. The shipper must first measure the shipment’s dimensions—length, width, and height—at its farthest points, including any packaging or the pallet. These three measurements, typically taken in inches, are multiplied to determine the total cubic inches of the shipment. This total is then divided by 1,728 (the number of cubic inches in one cubic foot) to find the shipment’s cubic volume.
The final step is to divide the shipment’s total weight in pounds by the calculated cubic feet. The resulting figure, expressed as pounds per cubic foot, is the density value used to reference an NMFC density chart or calculator to find the corresponding freight class. Accuracy is paramount because a minor error in dimension or weight can shift the density into a higher, more expensive freight class.
Consequences of Misclassification
Improperly classifying a shipment can lead to significant financial penalties and logistical complications. Carriers utilize sophisticated measuring and weighing devices upon receiving freight and will inspect a shipment if the provided information seems inaccurate. If the carrier determines the actual dimensions or weight place the commodity into a higher freight class than declared, the shipment is re-weighed or re-classed.
This re-classification results in an invoice adjustment, commonly known as a re-bill or chargeback. The shipper is retroactively charged the difference between the quoted rate and the correct rate, often with an added inspection fee. Misclassified freight can also lead to transit delays because the carrier must stop the shipment to correct the paperwork. Frequent misclassification can strain the business relationship between the shipper and the carrier, impacting future service and pricing.
Differences from Parcel and Full Truckload Shipping
The freight classification system is a distinctive feature of LTL shipping and is not used in other common modes of transport. Standard parcel shipping handles small packages, typically weighing less than 150 pounds. Parcel pricing uses a structure based on weight, destination zones, and dimensional weight, simplified for individual packages handled through automated sorting facilities.
Full Truckload (FTL) shipping, which involves a single shipper filling an entire trailer, also bypasses the need for freight classification. FTL pricing is determined by a flat rate based on the specific lane, equipment availability, fuel surcharges, and the distance traveled. Since FTL freight does not share space, the complexity of its density or liability in relation to other goods is irrelevant to the rate calculation.