If you ship less-than-truckload (LTL) freight, you’ve probably noticed that costs can vary widely for what seems like similar shipments. In fact, according to the American Trucking Associations, trucking moved nearly 11.5 billion tons of freight in 2024, and LTL shipments are only growing.¹ With so much freight moving around, carriers need a standard way to categorize goods so pricing, handling, and liability stay consistent. That’s where freight classes come in.
Understanding freight classes is one of the most important parts of keeping your costs predictable and your shipments moving without issues. Many shippers learn this the hard way when a carrier reclassifies their freight after pickup and adds surprise charges.
The good news is, once you understand how freight classes work, you can get it right the first time and avoid the headaches.
What Is a Freight Class?
In LTL shipping, a freight class is a numeric category that determines how much it costs to ship a particular type of product. Each handling unit falls into one of 18 numerical categories. The National Motor Freight Traffic Association (NMFTA) oversees this system through its National Motor Freight Classification (NMFC) book.
The NMFTA meets three times a year to update classifications, which means that categories can shift as new products hit the market or handling rules change. This system gives both shippers and carriers a common language for billing and transporting goods.
Freight classes range from Class 50 at the most favorable to Class 500 at the least favorable. The lower the class, the lower the cost to ship. Lower classes typically cover denser, easier-to-handle freight. Higher classes cover freight that is bulky, fragile, or carries higher risk.
Why Freight Classes Matter
Freight classes matter because they directly affect how much you pay. For example, Class 50 freight might cost a fraction of what Class 400 freight costs, even if both shipments weigh the same.
But cost is not the only factor. Freight class also tells the carrier how easy or difficult your shipment will be to transport. A dense pallet of bolts is hard to damage, so it receives a lower class. A pallet of ping pong balls, on the other hand, is not dense and easy to damage, so it falls into a higher class.
If you report your class incorrectly, the carrier can reclassify it after pickup. This usually comes with fees, shipment delays, and strained relationships with customers who expected timely deliveries.
4 Factors That Determine Freight Class
The NMFTA doesn’t pick numbers out of thin air. Freight classes are based on four main factors: density, handling, stowability, and liability.
1. Density
Density is often the most important factor. To calculate density, you need to measure and weigh your shipment.
Measure the extreme dimensions of the handling unit (length, width, height), including packaging or pallet.
Multiply length × width × height.
Convert cubic inches to cubic feet by dividing by 1,728.
Weigh the package or pallet.
Use the formula:
Density = Pounds / Cubic Feet
Higher density puts an item in a lower class. Why? Because high-density freight is less likely to get damaged and takes up less space.
Many shippers use the NMFTA’s ClassIT calculator to make this process easier.
2. Handling
Handling refers to how easy or difficult it is for carriers to move your freight. A uniform pallet of bricks is simple. A pallet of oddly shaped, fragile glass fixtures requires much more care. Some items, like hazardous materials or sensitive electronics, are assigned higher classes even if they are dense, simply because of the handling requirements.
3. Stowability
Stowability is how well your shipment can fit with others in the trailer. Freight that is stackable and rectangular is easy to stow. Freight that is oddly shaped, oversized, or restricted by federal or international regulations may be harder to stow and therefore gets a higher class.
4. Liability
Liability refers to the risk of transporting the freight. Goods that are perishable, fragile, hazardous, or high in value carry more liability. For example, smartphones are more likely to be damaged or stolen than a pallet of cement. This puts it in a higher class even if its density is similar to lower-class products.
Freight Class Examples
Here are various items and their possible classification depending on certain factors.
Freight Class | Product |
50 | Bags of cement |
60 | Tile |
70 | Bagged grain |
92.5 | Bulk packed clothing |
100 | Lawn mower |
125 | Alcohol |
200 | Smartphone |
250 | Fragile instruments |
300 | Uncrated bicycles |
400 | Fragile furniture |
500 | Fine art |
This table shows how density, handling, stowability, and liability all work together. Cement is dense and easy to move, so it can be in Class 50. A lawn mower takes up more space, is awkward to handle, and can be damaged, so it’s likely to be around Class 100. Fine art is delicate and high-value, so it’s Class 500.
How to Find the Right Freight Class
Finding the correct freight class is a process, but once you learn it, it becomes second nature.
Search by name. If the product is specifically listed in the NMFC book or in the NMFTA’s ClassIT tool, that’s the easiest path. Start with the nouns, then refine with adjectives.
Use general categories. If the product isn’t specifically listed, broaden your search to the most applicable category. For example, if you can’t find “garden hose,” look under “rubber products.”
Calculate density. If density is a factor for your product, you’ll need the exact dimensions and weight.
Check with your carrier or broker. They often provide guidance and can confirm your classification.
Ask NMFTA. If you are unsure, you can send a request directly to NMFTA’s classification team for clarification.
When Do You Need to Know Freight Class?
You need to know the freight class before you ship. It must be included on the Bill of Lading (BOL) along with the NMFC item number and description. Missing or incorrect information almost always results in reclassification charges.
Once you’ve identified the class, prepare your shipment: package it securely, label it, and contact your carrier for pickup. With the right class in place, you minimize surprises and increase the chances of a smooth, on-time delivery.
Common Challenges With Freight Classes
Shippers often run into problems with freight classes because:
Different carriers sometimes interpret classifications differently.
The NMFTA can update categories.
Some products fall into multiple possible classes depending on density or handling needs.
New products might not be clearly defined in the NMFC.
These challenges make it important to double-check your work and, when possible, use classification tools or experts.
Tips for Accurate Freight Classification
Always measure and weigh shipments carefully. Round up dimensions to the nearest inch.
Use consistent packaging to make density predictable.
Double-check NMFC item numbers before entering them on a Bill Of Lading.
Keep up with NMFTA updates to ensure you are not using outdated classifications.
Work with a trusted partner or platform that can help validate your class.
How Lojistic Helps Shippers With Freight Classes
Lojistic helps shippers eliminate the guesswork. Our platform provides visibility into your shipping costs, breaks down shipment activity by class, and helps support the prevention of costly reclassifications. By analyzing your freight spend across all your carriers, Lojistic can highlight opportunities to save money and streamline operations.
The NMFTA’s system of 18 categories is not going anywhere, and with LTL shipping only growing, accurate classification is more important than ever.
If you are ready to eliminate freight class confusion and optimize your shipping costs, Lojistic can help!
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Author
Gary McKenzie
Gary McKenzie
Chief Operating Officer
Gary McKenzie is the COO at Lojistic, where he oversees platform operations, product development, and service delivery. With more than 30 years of leadership experience spanning logistics, software, and transportation management, Gary has been instrumental in scaling the Lojistic spend management platform into a trusted solution for thousands of shippers.
Before joining Lojistic in 2012, Gary held senior leadership roles at companies including Technicolor, AMTREX Global Logistics, and Reuters Money Network. His background blends logistics strategy, IT architecture, and operational management, making him uniquely equipped to bridge technical innovation with real-world shipping challenges.
Gary holds a master’s degree in Organizational Management and a bachelor’s degree in Business Administration from Peru State College, where he also served as an adjunct instructor in e-commerce and communications.