Freight class explained: density, the NMFC, and how to find your class

0:00What is freight class?

Freight class is how LTL carriers price freight by how hard it is to move. Every shipment gets a class from 50 to 500. The lower the class, the less you pay per pound. The higher the class, the more you pay.

There are 18 classes, and they come from the National Motor Freight Classification. If you ship LTL, less than truckload, your class is one of the biggest things in your price, along with weight and distance.

0:29What decides your freight class?

What decides your freight class? Four things: density, handling, stowability and liability. Density is how heavy your freight is for the space it takes up. Handling is how easy it is to move across a dock and into a trailer. Stowability is how well it fits with other freight on the truck. And liability is how likely it is to be damaged, or to damage something else.

For most freight on a pallet, density is the one that decides it.

1:01Who sets freight class? NMFTA and the NMFC

Who sets freight class? The National Motor Freight Traffic Association, NMFTA, publishes the National Motor Freight Classification, the NMFC. The NMFC gives each kind of commodity an item number and a class. The NMFC belongs to NMFTA, and they protect it closely. That's why you won't find an official commodity class list on our site, or on most freight sites.

For the official item number on a specific product, use NMFTA's own lookup tool, ClassIT+, at nmfta.org. What anyone can work out is density, and for most palletized freight, density is what sets the class.

1:43How do you calculate freight density?

How do you calculate freight density? Measure the length, width and height in inches, at the longest points, including the pallet and anything that sticks out. Multiply them together, then divide by 1,728, the number of cubic inches in a cubic foot. That's your cubic feet. Then divide the weight in pounds by the cubic feet. That's your density, in pounds per cubic foot. Work it out for each pallet on its own.

For example, a standard 48 by 40 pallet, 48 inches tall, weighing 600 pounds, is about 53 cubic feet, and a density of about 11¼ pounds per cubic foot.

2:26How does density set your freight class?

How does density set your freight class? Since July 19, 2025, the NMFC uses a 13-level density scale, and more than 2,000 items were reclassified when it changed. The scale runs from class 50, for freight of 50 pounds per cubic foot or more, to class 400, for freight under 1 pound per cubic foot.

In between, 15 to just under 22½ pounds per cubic foot is class 70, and 10 to just under 12 is class 92.5. So our 600-pound pallet, at 11¼, is class 92.5. If your density lands exactly on a line, it takes the lower class: exactly 15 pounds per cubic foot is class 70, not 85.

3:17Why does a denser pallet get a lower class?

Why does a heavier pallet of the same size get a lower class? Because density goes up with weight. Take that same 48 by 40 by 48 pallet. At 1,000 pounds, it's about 18¾ pounds per cubic foot: class 70. At 250 pounds, it's under 5 pounds per cubic foot: class 175. Same size, same space on the truck, very different class.

Light, bulky freight takes up room without much weight, so it costs more per pound to ship. Stack your pallet square and tight, use a pallet that fits the load, and you ship freight, not air.

3:56When isn't freight class just density?

When isn't freight class just density? When the NMFC sets a class for the item itself. Fragile, hard-to-stow or high-liability freight can carry a class that density alone wouldn't give it, and classes like 77.5, 110, 150, 200 and 500 still exist for those items.

So treat a density class as a strong estimate. The NMFC item for your commodity is the official answer, and it's what your carrier goes by.

4:27What happens if your freight class is wrong?

What happens if your freight class is wrong? LTL carriers can inspect, reweigh and measure your shipment at their terminals. If the class on your bill of lading doesn't match what they find, they reclass it, and the difference shows up as an adjustment on your invoice after delivery. Getting the class right up front means fewer surprises on the bill.

4:47Free tools to estimate your freight class

Our free tools do the density math for you. Our freight class calculator takes your dimensions and weight and estimates your class by density. Our pallet calculator turns your boxes into pallets and gives a density class for each one. When you get a quote on our site, the quote works out the class from density, and you can change it if you know your NMFC class. And Allison, our AI freight agent, can estimate it for you in chat.

5:19Get a quote with the right freight class

Know your density, and you know your class. Get a quote at freightsidekick.com/freight-quote, with your class worked out from your dimensions and weight. Or call (877) 345-3838. Allison answers around the clock. Our freight class guide has the full density scale, at freightsidekick.com/resources/freight-class-guide.