What Is Freight Class? The Complete NMFC Guide
Freight class is a standardized rating - one of 18 numbers from 50 to 500 - that LTL (less-than-truckload) carriers use to price a shipment. It is assigned by the National Motor Freight Classification (NMFC) system, published by the NMFTA. A lower class (50) means dense, durable, easy-to-ship freight and a lower rate; a higher class (500) means light, bulky, fragile, or high-liability freight and a higher rate.
How is freight class determined?
Two factors set a commodity's class:
- Density - weight per cubic foot (pounds ÷ (L × W × H in inches ÷ 1,728)). For many commodities, density alone sets the class: the denser the freight, the lower the class and rate.
- The NMFC listing - the NMFTA assigns each commodity an NMFC item number and a class that also accounts for stowability, handling, and liability. Some items have a fixed class; others are graded by density brackets.
Use the freight class calculator for a density-based estimate, or the NMFC lookup to find the official listing for a commodity.
Full guide: how to calculate freight class →ยท8 worked examples →
The 18 freight classes (50–500)
There are exactly 18 freight classes. The table below shows each class, the kind of freight it typically covers, and how many of the 1,343 rated NMFC articles in the FreightAPIs database fall into it.
| Class | Typical freight | Articles in DB |
|---|---|---|
| 50 | Very dense, durable, low-risk (e.g. rough wooden shafts, bricks, sand) | 135 |
| 55 | Dense building materials (e.g. hardwood flooring, cement) | 78 |
| 60 | Dense machined goods (e.g. car accessories, steel parts) | 110 |
| 65 | Dense packaged goods (e.g. bottled beverages, books) | 77 |
| 70 | Moderately dense (e.g. mounted tires, car parts, food items) | 249 |
| 77.5 | Tires, bathroom fixtures | 55 |
| 85 | Crated machinery, cast-iron items | 215 |
| 92.5 | Mixed freight (e.g. portable forges, computers, monitors) | 39 |
| 100 | Boat covers, car covers, canvas | 174 |
| 110 | Cabinets, framed art | 12 |
| 125 | Small household appliances, garage doors | 51 |
| 150 | Auto sheet-metal parts, bookcases | 60 |
| 175 | Clothing, couches, stuffed furniture | 14 |
| 200 | Sheet-metal parts, aluminum tables | 33 |
| 250 | Mattresses, plasma TVs, telescopes | 19 |
| 300 | Wood cabinets, model boats, tables/chairs | 15 |
| 400 | Deer antlers, plastic baptistries - light, bulky | 5 |
| 500 | Lowest density, highest cost (e.g. ping-pong balls, gold dust) | 2 |
Counts reflect rated articles in the live FreightAPIs NMFC database and update as the data does.
Real classification examples
Each row is a real NMFC article - click the number to see the full listing.
Freight class vs. NMFC code - what's the difference?
They are related but not the same. The NMFC code (or item number) identifies the commodity - e.g. NMFC 157238 is "Tires, solid, NOI". The freight class (50–500) is the rating assigned to that commodity - tires are class 70. One commodity has one NMFC number; many commodities can share the same class.
Classify freight programmatically
Building a TMS, a freight-quoting tool, or an AI logistics app? The FreightAPIs NMFC API turns any product description into its NMFC code and freight class in one call - across 3,000+ articles. Free tier included.
Frequently asked questions
What is freight class?
Freight class is a standardized rating from 50 to 500 that LTL carriers use to price shipments, assigned by the National Motor Freight Classification (NMFC) system. There are 18 classes; lower numbers are dense, low-risk freight at lower rates, higher numbers are light, bulky, or high-liability freight at higher rates.
What are the 18 freight classes?
50, 55, 60, 65, 70, 77.5, 85, 92.5, 100, 110, 125, 150, 175, 200, 250, 300, 400, and 500.
How do I find the freight class for my product?
Either calculate it from density (weight in lbs divided by volume in cubic feet) using a freight class calculator, or look the commodity up in the NMFC database to get its official item number and assigned class.
Is freight class the same as the NMFC code?
No. The NMFC code (item number) identifies the commodity; the freight class (50-500) is the rating assigned to it. For example, NMFC 157238 "Tires, solid" is freight class 70.
What is the lowest and highest freight class?
Class 50 is the lowest (densest, cheapest to ship - e.g. bricks, sand). Class 500 is the highest (lightest and bulkiest, most expensive - e.g. ping-pong balls).