NMFC Codes and Freight Class
Freight class and NMFC codes are two of the most confusing parts of LTL shipping. This page explains exactly what they are, how they are worked out, and how they affect your price. The good news: FreightSimple takes care of all of this for you. You don’t need to calculate a freight class or look up an NMFC code to get a quote. This page is here for when you want to understand what is happening behind the scenes.
This applies to freight moving within the United States and to cross-border shipments between Canada and the US. Freight class and NMFC codes do not apply to domestic shipments within Canada, which carriers rate a different way.
If you just want the short version:
- Freight class is a number from 50 to 500 that describes how easy or hard your shipment is to transport. Lower numbers are cheaper to ship.
- NMFC codes identify the specific type of commodity you are shipping.
- For most freight, the class comes down to density, which is simply how much your shipment weighs for the space it takes up.
- FreightSimple calculates your class automatically from the weight, dimensions and commodity you enter, and we promise we will never send you an extra bill because the freight class was wrong.
What is freight class?
When you ship LTL (less-than-truckload), your shipment shares a trailer with freight from other companies. To price each shipment fairly and consistently, carriers need a standard way to describe how difficult a shipment is to carry. That standard is freight class.
There are 18 freight classes, ranging from class 50 (the cheapest to ship) to class 500 (the most expensive). The pattern is simple:
- Low class numbers mean dense, compact, easy-to-handle freight. A pallet of bricks or canned goods is low class.
- High class numbers mean light, bulky or awkward freight that takes up a lot of trailer space for very little weight. A pallet of ping pong balls or foam is high class.
Two shipments that weigh the same can have very different classes, and very different prices, depending on how much room they take up.
What is an NMFC code?
NMFC stands for National Motor Freight Classification. It is a catalogue, maintained by the National Motor Freight Traffic Association (NMFTA), that lists tens of thousands of commodity types. Every commodity has an NMFC item number that tells carriers exactly what is being shipped and how it should be classified.
It helps to think of it this way:
- The NMFC code answers “what is this?” (for example, “auto parts” or “plastic articles”).
- The freight class answers “how hard is it to ship?” (a number from 50 to 500).
The NMFC code is what links your specific commodity to the right class. For some commodities the NMFC code sets a fixed class. For most, the NMFC code points to a class based on density, which we explain below.
FreightSimple doesn’t require an NMFC code to give you a quote. However, if you do provide an NMFC code, we can give you more accurate and often better quotes. Our team is happy to help you find the right NMFC code for a commodity and save it to your dashboard so future shipments are even faster. This is usually a five minute conversation, so don’t hesitate to reach out via live chat or support@freightsimple.com.
How freight class is determined
Freight class is based on four characteristics of your shipment:
- Density: how much the shipment weighs for the space it takes up. This is the main driver of class for most freight.
- Stowability: how easily it fits alongside other freight on a trailer. Oversized, hazardous or oddly shaped items are harder to stow.
- Handling: how much care or special equipment it needs to load, unload and move.
- Liability: the risk of damage, theft or harm to nearby freight. Fragile, perishable or high-value goods carry more liability.
For the large majority of everyday freight, density is what decides the class. The other three factors matter most for unusual commodities such as hazardous materials, very fragile goods or items that are awkward to handle.
Density: the number that matters most
Density is simply your shipment’s weight divided by the space it occupies, measured in pounds per cubic foot (PCF). Here is how to work it out:
- Multiply length × width × height (in inches) to get cubic inches. Include the pallet and any overhang. See Measuring your Freight for how to measure correctly.
- Divide that by 1,728 to convert to cubic feet.
- Divide the total weight (in pounds) by the cubic feet. That gives you the density in PCF.
Worked example: a pallet measuring 48” × 40” × 48” that weighs 600 lbs.
- 48 × 40 × 48 = 92,160 cubic inches
- 92,160 ÷ 1,728 = 53.3 cubic feet
- 600 ÷ 53.3 = 11.3 lbs per cubic foot
Looking at the table below, 11.3 PCF puts this shipment at around class 92.5.
The denser your shipment, the lower the class, and the lower the price. This is why accurate dimensions matter so much. If a pallet is measured as taller than it really is, the density drops, the class goes up, and the price rises.
Density to freight class
This table shows the general relationship between density and class. Exact breakpoints are set by the NMFTA and can vary for some commodities, but this is a reliable guide for most freight. You do not need to use this table yourself. FreightSimple calculates the exact class for you.
| Density (lbs per cubic foot) | Freight 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 |
| 13.5 to under 15 | 77.5 |
| 12 to under 13.5 | 85 |
| 10.5 to under 12 | 92.5 |
| 9 to under 10.5 | 100 |
| 8 to under 9 | 110 |
| 7 to under 8 | 125 |
| 6 to under 7 | 150 |
| 5 to under 6 | 175 |
| 4 to under 5 | 200 |
| 3 to under 4 | 250 |
| 2 to under 3 | 300 |
| 1 to under 2 | 400 |
| Under 1 | 500 |
The 2025 NMFC changes
In July 2025, the NMFTA made one of the biggest changes to the NMFC system in decades. Effective July 19, 2025, more than 2,000 commodity items moved from the old commodity-based system to a density-based system, and the density scale was updated.
In practice, this means freight class now comes down to density for far more commodities than before. The goal is to make classification simpler, more consistent and easier to predict, and to reduce the surprises that used to come from misclassified freight.
What this means for you on FreightSimple: nothing changes in how you book. We keep our classification logic up to date with the NMFTA rules, so the class we calculate from your weight and dimensions reflects the current system. Getting your weight and dimensions accurate matters more than ever, because they now drive the class directly.
A few real-world examples
| Commodity | Typical density | Roughly what class |
|---|---|---|
| Bricks, tile, canned goods | High (very dense) | Class 50 to 65 |
| Machine parts, engines | Medium to high | Class 70 to 92.5 |
| Boxed auto parts, appliances | Medium | Class 92.5 to 125 |
| Furniture, fixtures | Low to medium | Class 125 to 175 |
| Lampshades, foam, ping pong balls | Very low (very bulky) | Class 250 to 500 |
These are general ranges to build intuition, not exact figures. The actual class always depends on the specific commodity and its real density.
How FreightSimple handles this for you
If you have shipped LTL before, you have probably bookmarked a freight class calculator and worried about getting the class wrong. Getting it wrong is a common cause of rebills, where the final bill is higher than the quote because the class was off.
FreightSimple is designed to remove this headache entirely. You never have to look up a class or do the density math yourself. There are two ways this plays out, and both are handled for you:
If you have the NMFC code on hand
If you already know the NMFC item number for what you are shipping, enter it on the quote. Carriers price more confidently when they know exactly what is on the trailer, so providing the NMFC code often gets you more accurate and better rates. If you ship the same thing regularly, save it once as a Saved Commodity with its NMFC class and item number, and every future quote auto-fills with the right values. No re-typing, no typos that lead to reclassification at the terminal.
If you don’t have the NMFC code
You don’t need it to get a quote. Our system works out the freight class automatically from the weight, dimensions and commodity description you enter, using the current NMFTA rules. You get an accurate quote either way. If you would like the exact NMFC item number pinned down, our team is happy to find it with you (usually a five minute conversation) and save it to your dashboard so it is ready for next time.
Because we take care of the classification, we promise we will never send you an additional bill because the freight class was wrong.
The one thing we need from you is accurate weight and dimensions, since those drive the class. If a carrier inspects your shipment and finds the measurements were different from what was entered, that can change the price. See Weight Reports and Inspections and Measuring your Freight for more.
If you think the class we are showing looks wrong, or you want help finding the right NMFC code for a commodity, just reach out via live chat or support@freightsimple.com. We are always happy to help.