Article Overview
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- Every commodity that ships via LTL needs a freight class.
- Getting your freight class correct is incredibly important (if you want accurate rates).
- There are 18 freight classes, ranging from 50-500, and it affects your rates.
- LTL shipments also need an NMFC code, which is not the same thing as freight class.
- 4 different things determine your freight’s NMFC code.
- Upcoming: In July 2025, there will be changes to NMFC codes that shippers need to know about.
While less than truckload (LTL) and full truckload freight shipping have several similarities, there are a few key differences, including how shipments are quoted.
To better calculate accurate LTL shipping costs, LTL commodities are broken up into several categories, known as freight class.
In this article, you’ll learn the basics of both freight class and NMFC codes so you can better understand the role they play in LTL shipping.
This knowledge is critical to getting an accurate LTL freight quote when shipping different commodities.
What Is an LTL Freight Class?
Freight class is an industry-wide numeric classification system used to categorize different commodities transported through LTL shipping.
The National Motor Freight Traffic Association (NMFTA) defines the freight classes and makes them available through the National Motor Freight Classification (NMFC) system.
There are 18 different freight classes, ranging from Class 50 to Class 500, and every single item that can ship via LTL will fall into one of those categories.
Why Freight Class Is Important in LTL Shipping
When shipping LTL, all commodities are not created equal.
Different products will have different freight classes, and your shipment’s freight class will have a significant impact on your rate.
In short, to get an accurate LTL quote, you need an accurate freight class.
Since the LTL carrier will load and unload your product multiple times, and multiple shippers’ freight will ride in the same trailer with yours, each pallet’s specifics — weight, dimensions, packaging, fragility, whether it’s stackable — all matter.
These factors determine how efficient your shipment is to move, how much effort it will take the carrier, and therefore, how much your shipment will cost.
Pro Tip: Don’t ever guess your freight class — it may cost you (literally).
Your LTL rate is not only based on the space your product takes up in a trailer, the freight’s density, stowability, handling needs and liability requirements all factor in (more on that below). Freight class takes all these factors into account.
LTL carriers will routinely check and re-weigh your freight after the initial pick up. If you get your freight class wrong, the carrier will re-class your shipment, and you could end up paying more (or less) than your initial rate.
Why Aren’t There Freight Classes in Full Truckload?
Commodity is much less important in full truckload shipping compared to LTL.
Why? In truckload shipping, your freight is not offloaded in-transit — it involves only one driver, one piece of equipment (trailer), and is delivered straight through from origin facility to destination. Furthermore, your freight does not share trailer space with any other shipper’s product.
An LTL carrier has to consider how they will load, off-load, re-load, transfer, stack and group each shipment with other shipments. In this more complex shipping method, the freight’s density on each pallet matters.
A full truckload driver, on the other hand, can make a much simpler yes/no assessment on the product weight, size and commodity at the time of booking. Whether you have 11 really heavy pallets or 22 really really light ones, it doesn’t really make any difference so long as it fits in one trailer and the tractor/trailer will be under the 80,000 lbs. weight limit.
How Freight Class Impacts Shipping Costs
High-density items (e.g., steel bars) will have a low freight class (e.g., 50) while low-density items (e.g., ping pong balls) will have a high freight class (e.g., 500).
The lower the freight class, the lower the rate — 50 is the least expensive.
The higher the freight class, the higher the rate — 500 is the most expensive.
What Commodities Make Up Each Freight Class?
Here are the 18 freight classes and the types of commodities they represent:
NMFC Code vs. Freight Class: What’s the Difference?
Every commodity has both a freight class and an NMFC code.
Freight class represents a category of items while NMFC codes relate to specific commodities within each of the 18 freight classes.
For example:
- Bricks: NFMC code = 32100.2, Freight Class = 50
- Steel Pipes: NMFC code = 51200, Freight Class = 50
Though each commodity has a freight class of 50, they have different NMFC codes.
NMFC classification is based on four main factors:
1. Density
Density refers to the weight per cubic foot of each piece, or the space an item occupies in relation to its weight.
Commodities with a higher density fall into a lower freight class and are easier to ship because they are more compact.
High-density commodities are, therefore, cheaper to ship than bulky, low-density items.
2. Handling
Handling relates to any unique handling or care requirements needed during transport.
Fragile or hazardous items may require special accommodations, which means they will fall into a higher freight class and cost more money to ship.
Size, weight, and shape can also impact the ease of handling, thus increasing the cost of shipping.
3. Stowability
Stowability accounts for how a commodity can be loaded and transported with other commodities.
If freight is hazardous, perishable, flammable, oddly shaped, or too heavy, it can be difficult to ship alongside other items.
If an item is difficult to stow with other items, it will have a higher freight class and be more expensive to ship.
4. Liability
Liability covers the likelihood of freight theft, damage, or damage to nearby loads.
If a commodity is perishable, has hazardous properties, or is combustible, for example, it will have a higher liability and will cost more to ship.
When combined, these four factors determine a commodity’s NMFC code.
Why NMFC Codes Are Important
NMFC codes are important because they help LTL carriers understand how difficult or easy it will be to ship a particular commodity.
Freight class is primarily only taking the freight’s density into account.
NMFC codes, on the other hand, are more specific and account for a variety of factors that can impact the efficiency of the shipping process.
Here are some of the factors NMFC codes consider:
- Weight, Length, and Height
- Commodity Type
- Density of the Freight
- Ease of Handling
- Value and Liability
- Packaging
How to Determine an NMFC Code for Your LTL Shipment
To find a specific NMFC code, you can use an NMFC classification tool, such as ClassIT, and go through the following steps.
- Search for the commodity within the tool.
(Be specific, and input the plural form of the item if no results are found.) - Select the commodity/NMFC that best fits the freight you are shipping.
- Calculate the density of your commodity with a freight calculator (you will need to know your commodity’s exact length, width, height, and weight).
- Select the correct class based on the density of your commodity.
Keep in mind, if your calculation is inaccurate, it can significantly impact your shipping costs.
If you want more help, a good LTL 3PL can also help you figure out your freight class and NMFC code.
2025 NMFC Code Updates: Changes to Freight Classification That Shippers Need to Know
In 2025, the NMFTA is making changes to the NMFC system, which will significantly impact the way LTL freight is classified, rated and billed.
The NMFTA has provided detailed resources for shippers, carriers, and 3PLs, but you can find a quick overview of what’s happening below.
What is happening to the NMFC codes?
The NMFTA is reviewing and revising NMFC system.
In total, they will be reviewing over 5,200 items (or codes), and will be changing, consolidating and phasing out many existing codes, with the goal of simplification and standardization the NMFC system.
For example, looking at the Aluminum analysis on the NMFTA change docket:
“42 items subject to the Aluminum generic heading would be canceled with reference to item 13120. Concurrently, item 13120 would be modified, and the description would be amended to provide a “viz.” format with classes predicated on the FCDC’s standard 13-subprovision density scale. Additionally, the generic heading, item 13100, would be amended to read “Aluminum Group.”
Or to put it more simply, they are rolling up 42 different codes for related aluminum products into one unified code. This is an example of how they’re approaching the whole system.
Looking at the NMFTA change site, they summarize the changes as follows:
- Standardized density scale for LTL freight with no handling, stowability, and liability issues.
- Unique identifiers for freight with special handling, stowability, or liability needs.
- Condensed and modernized commodity listings.
- Improved usability of the ClassIT classification tool.
Why are they changing the NMFC system?
The current system (as you can see in the aluminum example above) is needlessly complex.
The changes will make classifying freight easier and more efficient. According to the NMFTA, they have three primary goals:
- Simplify the NMFC: We’ll use a standardized approach based on density, handling, stowability, and liability.
- Enhance User Experience: The NMFC will be easier to use and understand.
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Increase Efficiency: Classifying freight will be more accurate on the first try.
When is the NMFTA changing NMFC codes?
They will be doing a phased approach, with phase 1 launching July 19, 2025.
You can find out every item that the NMFTA is reclassifying in phase 1 in the public Docket 2025-1.
How will the NMFC changes affect LTL rates?
It will be a case-by-case basis, depending on how freight is currently classified. Some NMFC items/codes will remain the same, others will change. Many categories will be simplified (less codes), while others may become more granular.
If freight you’re currently shipping is getting a new NMFC code, it may be more expensive, less expensive or stay the same.
One notable change in the NMFC system: a focus on standardized density ratings when assigning an NMFC code. Lower-density freight (lightweight, bulky items) may receive a new code with an increase in the associated freight class, which could raise freight costs. Make sure to reassess packaging and inventory to optimize for density.
What do shippers need to do to prepare?
It is very important that any company who ships LTL freight review their freight classifications prior to July 19, 2025.
It is every shipper’s responsibility to understand and accurately classify their freight.
If shippers are using an outdated classification, they could face unexpected freight charges due to misclassifications, confusion with their carriers and 3PL providers, and shipment delays.
In order to prepare, the NMFTA recommends shippers take the following steps:
- Review the bulletin (or use the item lookup tool, registration required) and verify whether or not your freight will be affected.
- Audit your systems (TMS, EMS, ERP, etc.) and update any classification changes.
- Communicate any changes with your carriers and 3PLs to make sure you’re aligned.
- Train your team to make sure they are aware of and understand any changes.
As LTL carriers adjust their operations to accommodate the new NMFC system, there may some changes in transit times, service options, and network availability, especially for freight that is shifting classification to higher-demand or more complex handling requirements.
The more you can communicate with your carriers, 3PLs and employees now, the better you can minimize disruptions and optimize costs.
Still need help? RXO is a leading LTL provider, and we’d be happy to help your business through these changes.
Additional resources from the NMFTA:
- Item lookup tool (requires registration)
- Shipper checklist
- Classification support (paid service)
- Webinars (paid service)
How to Get an Instant LTL Freight Quote
Once you know the freight class, weight, and dimensions of your commodity, you can determine the cost of shipping your LTL freight by utilizing an instant quoting tool.
You can get unlimited LTL quotes in RXO ConnectTM, our free digital freight platform.
Input your accessorials, add multiple commodities to a single shipment, build your own shipments — it has everything you need to get your freight moving.
