.png)
Learn how to determine a freight class for LTL shipping. Our guide covers density, NMFC codes, and stowability to help you avoid costly errors.
Before you can figure out your freight class, you need to look at your shipment through a carrier's eyes. They're primarily concerned with four things: density, handling, stowability, and liability. These factors are the building blocks of the National Motor Freight Classification (NMFC) system, which sorts all goods into one of 18 freight classes, from Class 50 to Class 500.
This classification directly sets the price for your Less-Than-Truckload (LTL) shipment.
Figuring out your freight class isn't just a box-ticking exercise—it has a real, immediate impact on your shipping budget. For anyone shipping LTL, getting this right is non-negotiable. It's the universal language carriers use to ensure pricing is fair and standardized across the board.
The whole system is managed by the National Motor Freight Traffic Association (NMFTA), which publishes the NMFC. This is the master guide that groups every conceivable commodity into those 18 classes. Think of it this way: the lower the class number, the lower your shipping cost.
It all comes down to how "transportable" your freight is. A lower freight class number means a lower shipping bill, plain and simple.
Here’s a classic example: imagine a pallet of dense steel bricks and a pallet of lightweight ping pong balls. Even if they take up the same exact space on the truck, the steel is far cheaper to ship. Why? It's sturdy, easy to stack, and takes up very little space for its weight, making it a much more efficient use of the trailer.
This is the central idea behind LTL freight. Since you're only paying for a portion of the truck, carriers need a consistent way to price items based on how much of a headache they are to move. If you're just dipping your toes into this shipping method, our guide on the LTL definition in logistics is a great place to start.
Get your classification wrong, and you're opening yourself up to hefty reclassification fees from the carrier. Those surprise charges can quickly erase any profit you expected to make.
At its core, the NMFC system evaluates every item based on four characteristics. Understanding these will give you a much better sense of where your shipment will land on the class scale.
These four elements work together to give carriers a complete picture of what they're transporting, allowing them to assign a freight class that accurately reflects the cost and risk involved.
Ready to see how your freight class affects your shipping cost? Get an instant price without the guesswork.
When it comes to the four main factors that decide your freight class, density is the big one. It's the first thing carriers look at, so getting this calculation right is job number one. The good news? The formula for finding your shipment's density—measured in pounds per cubic foot (PCF)—is pretty straightforward.
The real key is to measure everything after it’s packed and secured on the pallet. I can't stress this enough—accuracy is everything. A tiny miscalculation can easily bump you into a more expensive freight class, so grab that tape measure and get it right the first time. You'll need the length, width, and height of your entire palletized shipment, measured in inches.
Once you have those three measurements, you just need to plug them into a simple formula. Here’s how you get to your final PCF:
That final number is the most important piece of the puzzle for determining freight class. Remember, precise dimensions are just as critical as the final PCF. If you need a quick refresher on pallet sizes, we have a helpful guide on standard shipping pallet dimensions.
Let's walk through an example to see how it works. Say you have a standard 48" x 40" pallet, and with your freight stacked on top, the total height is 42". The all-in weight, including the pallet itself, is 500 pounds.
So, this shipment has a density of 10.71 PCF. The next step would be to take this number and check it against an NMFC density table to find its freight class.
This infographic really drives home how much density impacts your shipping costs.
As you can see, the denser your freight, the less space it takes up in the truck relative to its weight, which means a lower shipping bill for you. The effect of density is massive—an item with a PCF of 15 will almost always get a cheaper class than the same item at 5 PCF. It's the foundation of LTL shipping costs.
Tired of doing the math and want to ensure 100% accuracy? Our free tool calculates density and finds the right class for you instantly.
While density is king when it comes to freight class, it's not the only factor in the equation. Think of density as the starting point. Three other characteristics—handling, stowability, and liability—are what really tell the carrier how "transportable" your shipment is.
These factors explain why your freight class might be higher than what you'd expect based on density alone. They get to the heart of the real-world challenges of moving freight safely and efficiently from point A to point B.
Let's talk about handling. This is all about the level of difficulty involved in moving your freight from the dock, into the trailer, and back out again. Anything that requires special attention, equipment, or extra crew members is going to be flagged for its handling.
Imagine the difference between a neat, shrink-wrapped pallet of cardboard boxes and a giant, uncrated piece of industrial equipment. One is a simple forklift job; the other is a logistical puzzle.
Challenging handling often involves items like:
Bottom line? The more babysitting your freight needs, the more likely it is to be pushed into a higher freight class.
Ready to find out your class without the guesswork? Let us handle the complexities for you.
Next up is stowability, which is basically how well your freight plays with others. Carriers want to pack their trailers like a perfect game of Tetris to maximize space. If your shipment is oddly shaped, can't be stacked, or has pieces hanging off the pallet, it throws a wrench in their plan.
That wasted space costs the carrier money, so they pass that cost along in the form of a higher freight class for items that are difficult to stow.
Liability, on the other hand, is all about risk. It considers your shipment's value and how likely it is to be damaged or stolen. A pallet of brand-new laptops carries a much bigger financial risk for the carrier than a pallet of sandbags.
Because of this, high-value goods or items that are easily damaged get assigned a higher class. It's the carrier’s way of building in a little insurance for taking on the added risk of transporting your valuable cargo.
Alright, you've nailed down the four characteristics of your freight. Now it's time to translate that information into the language carriers speak: the National Motor Freight Classification (NMFC). This is the official playbook, the master list of every commodity you could possibly ship.
Your mission is to find where your specific product fits in.
Some items are straightforward. A certain piece of industrial equipment, for example, might always be Class 125, no matter how it’s packaged. For these kinds of products, the class is permanent because things like handling needs or liability risks are the main concern, not how much space it takes up.
But for most goods, density is king. To get the right freight class, you first need to find your item's unique NMFC code. Think of this code as a specific product ID that points you to the right set of classification rules.
With your NMFC code in hand, you'll look up its corresponding density table. This chart is your roadmap, showing you exactly where your calculated Pounds per Cubic Foot (PCF) lands. You might find that a PCF between 12 and 15 fits squarely into Class 85.
Pro Tip: Getting the NMFC code right is non-negotiable. I've seen countless shippers get hit with reclassification fees because they used the wrong code. Even if your density math is flawless, the wrong code will lead to the wrong class every time.
This code is also a critical piece of information for your Bill of Lading and other paperwork. If you want a deeper dive into what documents you'll need, our guide on essential documentation in shipping is a great resource.
To give you a clearer picture, here’s a simplified chart showing how density often translates to freight class. Keep in mind, this is just a general example—your specific item’s NMFC table is the ultimate authority.
As you can see, the process is pretty logical once you have the right tools. You just find where your density falls on the chart, and that gives you your class. No more guessing games.
Feeling a bit overwhelmed by all the codes and tables? You can skip the headache entirely. Let us handle the details and get you an accurate quote right away.
Knowing how to find your freight class is half the battle. The other half? Avoiding the simple, preventable mistakes that lead to costly reclassification fees. It happens all the time—shippers get their calculations slightly wrong, and carriers are quick to catch it during an inspection.
When a carrier spots a discrepancy, they don't just adjust the price. They issue a reclassification, which almost always comes with a hefty administrative fee that can seriously inflate your final bill. Staying meticulous is the best way to protect your budget.
This is, by far, the most frequent error I see. It’s so easy to get wrong if you’re not paying close attention.
Here are the usual suspects:
These might seem like small oversights, but they add up. Some industry estimates suggest that up to 25% of all freight shipments are reclassified, and it's often due to these exact issues. You can dive deeper into the importance of accurate freight classification and how it impacts shipping costs to see just how critical this is.
The other major tripwire is picking the wrong NMFC code. Your density calculation could be perfect, but if you apply it to the wrong item description, you’ll still end up with an incorrect freight class.
The NMFC database is incredibly specific. Assuming one code works for a "similar" item is a gamble that rarely pays off.
A reclassification isn't just a correction—it's a penalty. The carrier charges for the rate difference plus an inspection fee, turning a small mistake into a significant expense. The best defense is to double-check every single detail before the truck ever arrives.
The easiest way to sidestep these fees is to let an expert handle it. We verify every detail to ensure your quote is locked in and accurate from the start.
Even with the steps laid out, a few questions always seem to pop up. Let's tackle some of the most common ones we hear from shippers every day. Getting these right can save you a lot of headaches (and money).
This is a great question, and it's easy to get them mixed up.
Think of the NMFC code as a specific product identifier, like a SKU for shipping. It names the exact commodity you're sending, like "Wooden Ladders."
The freight class (e.g., Class 100) is the broader category that product falls into based on its overall "transportability"—density, handling, stowability, and liability. Often, the NMFC code itself will point you to a density-based chart to figure out the final freight class.
Nope, you can generally skip it. The entire freight class system was built for Less-Than-Truckload (LTL) shipping.
When you ship LTL, your freight is sharing space with other people's stuff. The class system creates a standardized way to price everything fairly. With a Full Truckload (FTL) shipment, you’re paying for the whole trailer, so the pricing is much simpler—usually a flat rate per mile or a daily rate.
A Word of Warning: If a carrier inspects your LTL shipment and finds the wrong freight class on your Bill of Lading (BOL), they will issue a reclassification. This isn't just a price adjustment; it comes with a hefty "re-class fee" that can really sting.
Getting the freight class wrong is an expensive mistake. It almost always triggers an inspection and a rate adjustment from the carrier. They'll correct the class on their end and send you a new bill for the difference.
But that’s not all. You’ll also get hit with that re-class fee I mentioned, which is pure penalty. If it happens repeatedly, it can damage your relationship with carriers, making it tougher to get good rates down the line. Accuracy isn't just about this one shipment; it's about keeping your entire logistics operation running smoothly.
Ready to ship without second-guessing your freight class? Get a guaranteed, accurate quote in just a few minutes.
