Freight Class and NMFC Codes: How to Find Yours
Freight class is a number from 50 to 500 that sets the price of an LTL shipment. Here's how density decides it, how to calculate yours, and what happens when the class on the bill of lading is wrong.
Freight class is a number from 50 to 500 that LTL carriers use to price a shipment. Low classes are dense, sturdy freight that is cheap to move. High classes are light, bulky or fragile freight that costs more. The classes are defined in the National Motor Freight Classification (NMFC), published by the National Motor Freight Traffic Association (NMFTA).
Freight class applies to less-than-truckload shipping. A full truckload is priced by the mile, and class does not enter into it.
Freight class and NMFC code are two different things
People use the terms as if they were one. They are not.
- The NMFC item number identifies the commodity. Every type of product has one.
- The freight class is the rating that item receives. There are 18 classes: 50, 55, 60, 65, 70, 77.5, 85, 92.5, 100, 110, 125, 150, 175, 200, 250, 300, 400 and 500.
You look up the item number for what you ship. The item tells you the class, or tells you to work the class out from density.
What decides the class
The NMFC rates freight on four characteristics.
| Characteristic | What it measures |
|---|---|
| Density | Pounds per cubic foot. Heavier for its size means a lower class. |
| Handling | Whether it needs special care or equipment to load and move. |
| Stowability | Whether it fits easily with other freight. Odd shapes and hazardous goods do not. |
| Liability | Value, fragility, and the chance of theft or damage. |
Density carries the most weight. In July 2025 the NMFTA moved a large share of commodities onto a single standard density scale, so for most freight the class now comes straight from the density calculation. Items with real handling, stowability or liability concerns keep their own rules.
How to calculate density
Measure the shipment as it will ship: on the pallet, wrapped, including the pallet itself.
- Measure length, width and height in inches, at the widest and tallest points.
- Multiply them together to get cubic inches.
- Divide by 1,728 to get cubic feet.
- Divide the total weight in pounds by the cubic feet.
A worked example, for one pallet that measures 48 × 40 × 50 inches and weighs 600 lb:
| Step | Math | Result |
|---|---|---|
| Cubic inches | 48 × 40 × 50 | 96,000 |
| Cubic feet | 96,000 ÷ 1,728 | 55.56 |
| Density | 600 ÷ 55.56 | 10.8 lb per cubic foot |
For more than one pallet, add up the cubic feet of all of them and divide the total weight by that.
The standard density scale
This is the 13-step density scale the NMFC uses for density-rated freight.
| Density (lb per cubic foot) | Class |
|---|---|
| 50 or more | 50 |
| 35 to under 50 | 55 |
| 30 to under 35 | 60 |
| 22.5 to under 30 | 65 |
| 15 to under 22.5 | 70 |
| 12 to under 15 | 85 |
| 10 to under 12 | 92.5 |
| 8 to under 10 | 100 |
| 6 to under 8 | 125 |
| 4 to under 6 | 175 |
| 2 to under 4 | 250 |
| 1 to under 2 | 300 |
| Under 1 | 400 |
The 600 lb pallet above, at 10.8 lb per cubic foot, is class 92.5.
Not every commodity follows this table. Some items carry a fixed class whatever they weigh. Confirm the item for your product in ClassIT, the NMFTA's lookup tool, or ask your carrier or broker to confirm it.
What happens when the class is wrong
LTL carriers measure and weigh freight at their terminals, often with automated dimensioning equipment. If the shipment does not match the bill of lading, the carrier corrects it.
- Reweigh. The actual weight is higher than stated. You are billed for the difference.
- Reclassification. The measured density puts the freight in a different class. You are billed at the new class, and many carriers add an inspection fee.
Both arrive as a corrected invoice after delivery. Declaring a lower class to get a lower quote does not save money. It moves the cost to a later invoice and adds a fee.
Declaring a class that is too high costs you too. Nobody sends a correction when you overpay.
How to get it right
- Weigh and measure the finished pallet. Include packaging and the pallet.
- Do not estimate dimensions. A few inches of overhang changes the cubic feet and can change the class.
- Find the NMFC item number once for each product you ship regularly, and keep it on file.
- Put class, NMFC item number, weight and dimensions on the bill of lading. See how to read and fill out a bill of lading.
- Keep a photo of the pallet on the scale. It is your evidence if you dispute a reweigh.
FAK: one class for mixed freight
If you ship many products of different classes, a carrier may agree to a freight-all-kinds (FAK) rate. Under an FAK, a range of classes is rated as a single agreed class. It makes quoting simpler and cuts down on reclassification disputes. FAK terms are negotiated with the carrier and written into the pricing agreement.
Getting an LTL quote
To quote LTL we need the weight, the dimensions and the class or NMFC item. Lancashire Freight returns a binding all-in rate in 60 seconds, locked for 48 hours. If you are not sure of your class, give us the measured dimensions and weight.
FAQ
What is freight class?
Freight class is a rating from 50 to 500 that LTL carriers use to price a shipment. It is based mainly on density, along with how hard the freight is to handle, how well it stows, and how much liability it carries.
What is an NMFC code?
An NMFC code is the item number that identifies a commodity in the National Motor Freight Classification. The item number determines the freight class, either directly or through the density of the shipment.
How do I calculate freight class?
Multiply the length, width and height of the shipment in inches, divide by 1,728 to get cubic feet, then divide the weight in pounds by the cubic feet. That gives density in pounds per cubic foot, which you match to a class on the density scale.
What is the difference between freight class and NMFC?
The NMFC item number identifies what the product is. The freight class is the rating assigned to that product for pricing. One is a catalog number and the other is the rate category.
What happens if I use the wrong freight class?
The carrier inspects the shipment, corrects the class, and sends an adjusted invoice for the difference. Many carriers also charge an inspection or reclassification fee.
Does freight class apply to full truckload shipments?
No. Freight class is used for LTL pricing. A full truckload is priced by the mile for the use of the whole trailer, so the class of the freight does not set the rate.
What is the lowest freight class?
Class 50 is the lowest and the cheapest to ship. It covers freight with a density of 50 pounds per cubic foot or more that is durable and easy to handle.
Get an LTL quote with a binding all-in rate, locked for 48 hours.