What is Freight Class Explained
Detention charges apply when freight equipment or vehicles exceed agreed free time, covering container returns, loading delays, causes, cost impacts, prevention methods, and key differences from demurrage in European logistics operations.
Freight class is a North American classification system that assigns LTL shipments a rating between class 50 and class 500 based on density, stowability, handling, and liability. The rating determines the transport cost. It applies to domestic freight moving inside the United States, Canada, and Mexico.
What Does Freight Class Mean in LTL Shipping?
Freight class is a standardised commodity classification that groups goods by how efficiently they move through an LTL network. The National Motor Freight Traffic Association publishes the classification directory, the NMFC, which assigns every commodity an item number and a corresponding class. Carriers build their rates from that class. It ranks among the haulage glossary terms where the same word carries different meaning depending on which continent the shipment moves through.
LTL exists because most shipments do not fill a trailer. A carrier collects from several shippers, loads them into one vehicle, and each shipper pays a share of the run. Splitting that cost by weight alone breaks down immediately — a pallet of steel fittings and a pallet of foam packaging weigh the same and occupy completely different amounts of trailer space. Freight class is the mechanism that makes the split workable.
What Are the Four Freight Classification Factors?
Four factors set a shipment's class: density, stowability, handling, and liability.
Density is the space a shipment occupies relative to its weight, and it drives the classification harder than the other three combined. Dense freight fills a trailer efficiently. Light, bulky freight consumes space that heavier goods would otherwise use.
Stowability covers how the freight sits alongside other loads. Hazardous goods barred from travelling with certain commodities, items protruding beyond the pallet footprint, and loads with no flat load-bearing surface all rate worse. A pallet that cannot be stacked blocks the trailer height above it for the whole run.
Handling covers what happens each time the freight moves. Standard goods go on and off a trailer with a forklift and need nothing further. Awkward shapes, fragile items, and hazardous cargo need care, extra time, or specific equipment, and every terminal touch adds cost.
Liability covers theft risk, damage risk, and the carrier's exposure if the goods are lost. Perishables, high-value electronics, and breakable goods rate higher. Where liability drives the classification, density still applies alongside it.
How is Freight Density Calculated?
Freight density is weight in pounds divided by volume in cubic feet. Reaching the volume figure takes one conversion step, because freight is measured in inches and density is expressed per cubic foot.
Measure length, width, and height in inches, including the pallet and all packaging. Multiply the three figures for cubic inches. Divide by 1,728 — the number of cubic inches in a cubic foot. Then divide the shipment weight in pounds by that cubic feet result.
A pallet measuring 48 × 40 × 50 inches gives 96,000 cubic inches. Divided by 1,728, that is 55.5 cubic feet. At a gross weight of 600 lbs, the density comes out at 10.8 lbs per cubic foot.
Measure the pallet, not the product. Overhang, void space inside cartons, and packaging material all count toward the volume the carrier records at the terminal.
What Are the 18 Freight Classes?
18 classes run from class 50 to class 500. Since July 2025, the NMFC rates freight with no handling, stowability, or liability concerns on a 13-tier density scale, measured in pounds per cubic foot. The other five classes — 77.5, 110, 150, 200, and 500 — apply to commodities whose NMFC item also reflects those factors. Density falls as the class number rises, and the rate rises with it.
| Class | Density (lbs per cubic foot) |
|---|---|
| 50 | 50 or more |
| 55 | 35 to under 50 |
| 60 | 30 to under 35 |
| 65 | 22.5 to under 30 |
| 70 | 15 to under 22.5 |
| 85 | 12 to under 15 |
| 92.5 | 10 to under 12 |
| 100 | 8 to under 10 |
| 125 | 6 to under 8 |
| 175 | 4 to under 6 |
| 250 | 2 to under 4 |
| 300 | 1 to under 2 |
| 400 | Under 1 |
Class 50 is the cheapest band because dense, stackable freight lets a carrier reach the trailer's weight limit before running out of floor space. Class 400 is the most expensive band on the density scale because the trailer fills with volume long before it approaches its payload capacity.
How Does Freight Class Affect LTL Rates?
Class sets the rate because it measures what a shipment costs the carrier in trailer space and handling rather than what it weighs. Two consignments at 500 lbs each price differently when one sits at class 60 and the other at class 250, and the gap widens as the distance grows.
The carrier's economics are straightforward. A trailer has a weight limit and a floor area, and profitability depends on approaching both. Dense freight moves the load toward the weight limit. Bulky freight consumes floor area without contributing weight, and that space cannot be sold to anyone else on the same run.
Packaging affects the outcome directly. The same goods palletised tightly, with no overhang and no void space, fall into a lower class than the same goods loaded loosely. On repeat lanes that difference compounds across every shipment of the year. The same principle drives pricing on a partial truck load, where the shipper pays for the floor space the consignment occupies rather than for the trailer as a whole.
What Happens if the Wrong Freight Class is Declared?
The carrier re-weighs and re-measures the shipment at the terminal, applies the correct class, and issues a rate adjustment plus an inspection fee. On many carrier tariffs, the corrected rate carries none of the discount that applied to the original booking.
Reclassification is a leading cause of an LTL invoice failing to match its quote. It starts with a declared class copied from a previous shipment, or a class selected because it looked close enough. The carrier's scale and dimensioner settle the question and the adjustment follows.
Disputing a reclassification requires documented dimensions and weight recorded at dispatch, before the goods left the origin site. Without that record there is nothing to set against the carrier's terminal measurement. Reclassification adjustments, detention, and demurrage all reach the customer the same way — after delivery, on an invoice, with the shipment long gone — and the Go Trans guide to European freight terminology separates each one by what triggers it and who issues it.
Does Freight Class Apply to European Road Freight?
Freight class does not apply to European road freight. European carriers price LTL on loading metres and chargeable weight — the higher of the volume-based weight and the actual deadweight in shipping. No carrier moving goods between Belgium, Germany, France, or the Netherlands asks for a class code.
European carriers need pallet dimensions, gross weight, and confirmation of whether the load is stackable. The LDM meter figure — the length of trailer floor a consignment occupies — does the job that freight class does in North America, and the pricing follows directly from it. Go Trans arranges part load freight from Belgium on that basis, matching consignments to available trailer space on each lane.
One scenario puts freight class in front of a European shipper: goods sold to a US consignee that continue by domestic American LTL after import clearance. The transatlantic leg prices on its own terms. The American road leg needs a class.
Frequently Asked Questions
What does class 70 freight mean?
Class 70 covers freight with a density between 15 and 22.5 lbs per cubic foot — machinery, engine components, car parts, and cased food products. A large volume of palletised industrial freight falls into this band, which puts class 70 among the most frequently used ratings in North American LTL. Rates sit in the lower-middle of the scale.
What is class 200 in freight?
Class 200 applies to commodities whose NMFC item assigns it because of handling, stowability, or liability, not density alone. Since July 2025, freight rated purely on density at 4 to under 6 lbs per cubic foot falls into class 175 instead. Freight at class 200 takes substantial trailer space or care relative to its weight, which puts the rate well above mid-scale classes despite the modest weight involved.
Does freight class apply to full truckload shipments?
Freight class does not apply to FTL. A full truckload shipper pays for the entire trailer regardless of what fills it, so there is nothing to allocate between parties. Classification exists to divide cost between shippers sharing one vehicle. Full container loads and parcel shipments price on separate systems for the same reason.
What is the difference between freight class and an NMFC item number?
The NMFC item number identifies the commodity within the classification directory. The class is the rating that item carries. One is the entry, the other is the output of applying the classification rules to it. Classification disputes trace back to the wrong item number being used far more often than to a misread class.