What a freight class is
A freight class is a category in the National Motor Freight Classification, or NMFC, which is maintained by the National Motor Freight Traffic Association (NMFTA). LTL carriers use the class, together with the lane, the weight, and their own pricing, to rate a shipment. Classes range from 50 to 500. As a general rule, lower classes are denser and easier to handle, and they tend to rate lower per pound. Higher classes are lighter, bulkier, harder to stow, or higher risk, and they tend to rate higher.
The class is not the same thing as an NMFC item number. The item number identifies the commodity, or a group of commodities, in the classification. The item’s provisions then assign a class — sometimes a single class, and sometimes a class that depends on density or another characteristic. That is why there is no one “NMFC number for class 50.” Many different items can land in the same class.
This system applies to less-than-truckload freight. Full truckload rates are not built the same way. If you are choosing between a few pallets and a dedicated trailer, start with our FTL vs LTL guide, then come back here if LTL is the right mode.
The four characteristics NMFTA uses
NMFTA states that classification is based on four transportation characteristics: density, handling, stowability, and liability. Those four traits, taken together, describe how practical the freight is to carry in a mixed trailer.
- Density is how much the freight weighs for the space it occupies, usually expressed in pounds per cubic foot. Denser freight generally receives a lower class.
- Handling is how readily the freight can be loaded, unloaded, and moved through a terminal. Odd shapes, fragility, and poor packaging make handling harder.
- Stowability is how easily the freight can be loaded with other shipments. Uniform, stackable pallets stow more easily than irregular or non-stackable freight.
- Liability is the risk of loss, damage, theft, or harm to other freight. Higher-risk commodities can be assigned a higher class even when they are reasonably dense.
For many commodities, density is now the main driver. On July 19, 2025, changes from NMFTA Docket 2025-1 took effect. According to NMFTA, the previous 11-sub density scale was replaced with a more detailed 13-sub density scale, more than 2,000 items moved to full density-based classification, and many generic headings were consolidated. Items with unusual handling, stowability, or liability characteristics are marked separately. Always confirm the current class for your commodity; the official source is the NMFC, including NMFTA’s ClassIT+ tool.
How to calculate density
Density is gross weight divided by volume in cubic feet. Use the finished, packaged shipment, including the pallet:
Density (lb/ft³) = weight in pounds ÷ (length × width × height in inches ÷ 1,728)
Here is a worked example, for illustration only. A pallet that measures 48 by 40 by 48 inches, including the pallet height, has a volume of 48 × 40 × 48 ÷ 1,728, which is 53.3 cubic feet. If the gross weight is 620 pounds, density is about 11.6 pounds per cubic foot. That number is then applied to the NMFC item that actually describes the commodity. Some items use the standard density scale. Others have their own provisions.
NMFTA has published the high-density end of the current 13-sub scale: 30 but less than 35 pounds per cubic foot is class 60, 35 but less than 50 is class 55, and 50 or greater is class 50. We are not reprinting a full unofficial class chart here, because mid-range breaks should be confirmed in the current NMFC rather than copied from a third-party table. If you send us the dimensions and weight, we can work with the density and the commodity description when we quote.
Measure after the freight is wrapped, and weigh the pallet and the product together. Carriers measure the same way. If the cartons hang over the edge of the pallet, the overhang is part of the dimensions, and the density figure will be lower — which can mean a higher class.
Why the class changes the quote
On LTL, you are paying for space and handling, not for a dedicated trailer. A dense, compact shipment uses less of the trailer for the weight it contributes, so it usually rates more favorably than a light, bulky shipment of the same weight. That is the practical reason class exists.
Class is only one input. The origin and destination, the weight, extra services such as a liftgate or an appointment, and the carrier’s own pricing all matter. Two shipments in the same class can still quote differently on different lanes or dates. Our team does not post standing LTL prices for that reason. A number on a page would not be the number we could honor when you are ready to ship.
What happens if the class is wrong
If the class or the dimensions on the bill of lading do not match what the carrier inspects, the carrier may reclassify the shipment and adjust the charges. That is one of the more common sources of an LTL invoice that does not match the quote. The fix is not to pick a lower class in the hope of a lower rate. The fix is to describe the freight accurately — commodity, weight, dimensions, and whether the pallets can be stacked — before the freight is picked up.
You do not have to arrive with a finished NMFC item number. If you already have one, include it in the notes. If you do not, send the details above and we will take it from there.
What to send us so we can quote correctly
- Pickup and delivery city, state, or ZIP
- Pallet count, and length, width, and height of each pallet if you have them
- Gross weight, including the pallets
- Whether the pallets can be stacked
- A short commodity description
- Any liftgate, appointment, limited-access, or inside delivery need
- The NMFC item or class, only if you already have it
For a broader walkthrough of every form field, see how to get a freight quote. For how to build and label the pallets themselves, see how to ship pallets.