Freight Class & NMFC Guide
Freight Class Matters More Than Most Shippers Realize
Freight class, NMFC item numbers, density, handling, stowability, and liability can all affect LTL pricing. Amark helps customers review shipment details so quotes and invoices are based on better information.
What Is NMFC?
The National Motor Freight Classification system helps identify and classify commodities moving by LTL freight. NMFC information can affect how a shipment is rated, priced, handled, and reviewed by carriers.
What Is an NMFC Item Number?
An NMFC item number identifies a commodity or commodity group. When available, the correct NMFC item can help support accurate freight classification and reduce confusion during rating or invoice review.
What Is Freight Class?
Freight class is used in LTL shipping to help determine pricing. Class can be affected by shipment density, handling, stowability, and liability.
How to Find Your NMFC Number
Your NMFC number (also called the NMFC item number) tells the carrier exactly how your product is classified. Here are the most reliable ways to find it:
- Check past bills of lading and carrier invoices. If you have shipped the same product before, the NMFC number and class are usually printed on the paperwork. Make sure that shipment was not reclassed.
- Ask your supplier or manufacturer. Many manufacturers already know the NMFC item for the products they sell and can share it with you.
- Use the official ClassIT tool. The National Motor Freight Traffic Association (NMFTA), which publishes the NMFC, offers ClassIT, its official online lookup. It requires a subscription, so it is most useful for companies that ship often.
- Ask your freight broker. At Amark, we help customers confirm the right NMFC number and class before pickup, as part of every quote.
Since July 2025, many NMFC items are classed mainly by density. That means even with the right NMFC number, you still need accurate weight and dimensions to land in the correct class.
How to Avoid Reclass Fees
A reclass happens when the carrier inspects your freight and decides it belongs in a different class than the one on your bill of lading. It usually means a higher bill plus an extra fee. To avoid it:
• Measure and weigh every shipment, including the pallet.
• Use the correct NMFC item number, not a guess or an old number.
• Describe the product clearly on the bill of lading, not just “parts” or “merchandise.”
• Recheck your NMFC numbers once a year, since the classification can change.
Not sure which NMFC number fits your product? Request a quote and our team will help you confirm it before your freight moves.
Why Freight Class Accuracy Matters
Incorrect freight class can lead to:
- Quote changes
- Reclasses
- Additional carrier charges
- Billing disputes
- Delayed invoice approval
- Customer confusion
- Weaker documentation if a billing issue arises
What Information Helps Determine Class?
Amark may ask for:
- Commodity description
- NMFC item number, when available
- Length, width, and height
- Total weight
- Packaging type
- Stackability
- Handling requirements
- Value or liability concerns
- Photos or product details when needed
Freight Class Calculator
Enter shipment dimensions and weight to calculate density and estimated freight class.
A calculator can help estimate density, but it should not be treated as final classification. Final class may depend on NMFC language, commodity description, packaging, carrier interpretation, and applicable rules.
Freight Class FAQs
Measure the length, width and height of the full shipping unit in inches, including the pallet. Multiply them and divide by 1,728 to get cubic feet. Then divide the total weight in pounds by the cubic feet to get the density. then use our freight class calculator to find your class.
An NMFC item number identifies the commodity being shipped. That item then tells you the freight class, either a fixed class or a class based on density. In short, the NMFC item describes what the freight is, and the freight class decides how it is rated.
On July 19, 2025, the National Motor Freight Classification moved many more commodities to density-based classes and introduced a standard 13-level density scale. As a result, measuring weight and dimensions accurately matters more than ever, because density now decides the class for a larger share of LTL freight.
Yes. Carriers measure the full handling unit, so the pallet, packaging and any overhang should be included in both the weight and the dimensions. Leaving out the pallet is one of the most common reasons for a reclass.
If a carrier inspects a shipment and finds that the declared class, weight or dimensions are wrong, it can reclass the freight and bill the difference. Some carriers also add an inspection fee. Accurate details on the bill of lading are the best way to avoid it.
Freight classes range from 50 to 500. Class 50 is for very dense, durable freight and usually costs the least to ship. Higher classes are for light, bulky or fragile freight that takes up more trailer space, and they cost more per pound.
Unsure About Freight Class?
Send Amark the shipment details and our team can help review the information needed for a more accurate LTL quote.
