Shipping goods via Less-Than-Truckload (LTL) is the standard method for businesses moving shipments that do not require the entire capacity of a semi-trailer. LTL involves consolidating multiple shipments from various customers onto a single truck, which makes cost determination complex. To standardize pricing across this consolidated model, the shipping industry mandates a uniform freight classification system. Accurately determining this classification is necessary for managing logistics budgets and ensuring smooth transit.
What is LTL Freight Class and Why is it Necessary?
The LTL freight class system is a standardized framework developed and maintained by the National Motor Freight Traffic Association (NMFTA). This system categorizes all commodities into one of 18 classes, ranging from Class 50 to Class 500. This numerical assignment directly correlates to the difficulty and cost associated with transporting the item.
Class 50 represents the least expensive freight to ship, typically items that are dense, durable, and easy to handle. Conversely, Class 500 is assigned to commodities that are lightweight, fragile, or irregularly shaped, making them the most costly to transport per pound. Carriers rely on this classification to ensure consistent pricing and that revenue accurately reflects the handling, space, and liability requirements of the freight they transport. Without this system, rate negotiations would be inconsistent and highly subjective, leading to pricing instability within the industry.
The Four Characteristics That Influence Class
The final freight class is influenced by four distinct transportability characteristics defined by the NMFTA:
- Density: Measures the weight of the item in relation to the space it occupies, expressed as pounds per cubic foot. Higher density typically results in a lower freight class and shipping cost.
- Stowability: Assesses how easily an item can be loaded and transported alongside other shipments. Freight that is long, oddly shaped, or cannot be stacked is considered less stowable, potentially increasing its class.
- Handling: Refers to the ease or difficulty a carrier faces when loading, unloading, and moving the freight. Items requiring specialized equipment or careful manual labor may receive a higher classification.
- Liability: Accounts for the risk of the freight being damaged, stolen, or causing damage to other commodities in the trailer.
For the majority of common LTL shipments, the calculated density remains the primary determinant for the final classification.
Step-by-Step Guide to Calculating Density
Accurately calculating density is the first concrete step in classifying most standard LTL shipments, as it quantifies the space-to-weight ratio. This calculation is essential for determining the baseline classification for common freight.
Measure Volume
The process begins with precise measurement of the packaged freight, determining the longest length, widest width, and tallest height in inches. If the shipment consists of multiple identical pieces, calculate the dimensions for a single item and multiply by the quantity. Multiply these three dimensions together to yield the total cubic inches occupied by the shipment.
Convert to Cubic Feet
Convert the total cubic inches into cubic feet by dividing the measurement by 1,728 (the number of cubic inches in one cubic foot). This achieves the required standardized volume measure.
Determine Gross Weight
Accurately determine the gross shipping weight of the entire consignment in pounds. This weight must include the product itself, all internal packing materials, and the external pallet or container used for transport. Using a calibrated, certified scale prevents discrepancies that could lead to later audits, making this measurement a verification point for carriers.
Calculate Density
The final density figure, expressed as pounds per cubic foot (pcf), is calculated by dividing the total weight in pounds by the total cubic feet. This density value is used to locate the corresponding freight class for the shipment.
Mapping Density to the Freight Class Number
The calculated pounds per cubic foot (pcf) value serves as the input for a standardized density-to-class chart. This chart organizes the 18 freight classes into specific density ranges, translating the physical properties of the shipment to its numerical classification. Carriers rely on this consistent mapping to ensure uniformity in rating.
For instance, a shipment under one pcf typically maps to the highest classification, Class 500. Conversely, highly dense freight measuring 50 pcf and above falls into Class 50, the lowest cost classification. A mid-range density between 9.0 and 10.5 pcf generally corresponds to Class 85. Recognizing the general relationship—higher density means a lower class number—is useful for initial planning and cost estimation.
When Density Does Not Apply: The National Motor Freight Classification (NMFC)
While density is the primary factor for many goods, the governing system is the National Motor Freight Classification (NMFC), which assigns specific codes to all transportable commodities. Every LTL item must be identified by a corresponding NMFC code, which accounts for stowability, handling, and liability, and can override the density calculation.
Certain commodities are assigned a fixed, “commodity-based” classification regardless of measured density. Items like rolled carpet, chemicals, or specific furniture types have inherent handling or liability risks that necessitate a predetermined class. For instance, a chair may have a fixed class due to its awkward shape and low stackability, even if its density suggests a lower class.
The NMFC index is complex, containing thousands of codes, many of which also feature “class exceptions” based on packaging or form. Shippers must consult the official NMFC manual or digital database to find the code that precisely matches their product description. Using an incorrect or overly general NMFC description is a common source of carrier audits and reclassification.
Some shippers negotiate a contracted rate known as a Freight All Kinds (FAK) agreement with their carriers. An FAK allows a shipper to move multiple products that would normally fall into various classes under a single, predetermined, and generally lower class number. This negotiated exception simplifies billing and can reduce costs, but it remains a contractual deviation from the standard NMFC rules.
Verification and Avoiding Reclassification Fees
After determining the correct NMFC code and calculating the class, a thorough verification process is necessary to prevent costly errors. Shippers must double-check all measurements, ensuring length, width, and height are recorded precisely to the nearest inch, and that the weight is accurate. Proper, protective packaging must also be confirmed, as inadequate packing affects the liability component of the class.
The classification details, including the NMFC code, description, weight, and class, must be clearly documented on the Bill of Lading (BOL). This document serves as the legal contract between the shipper and the carrier, and any inaccuracies found later will trigger an audit. When a carrier discovers a discrepancy, they perform a reclassification. This results in a substantial reclassification fee, coupled with the difference in freight charges applied retroactively. To mitigate this risk, many shippers utilize carrier-provided online classification tools or verification services offered by third-party logistics (3PL) providers. These platforms offer an additional layer of confirmation before the shipment is finalized and dispatched.