Everything you need to know about the National Motor Freight Classification system, from understanding freight classes to finding the right NMFC code for your shipments.
What is an NMFC Code?
An NMFC code (National Motor Freight Classification code) is a standardized numeric identifier assigned to commodities shipped via LTL (Less-Than-Truckload) freight. These codes create a uniform classification system that carriers use to determine shipping rates based on the characteristics of the freight being transported.
Think of NMFC codes as the universal language of freight shipping. Just as ISBN numbers identify books, NMFC codes identify and classify freight commodities. When you ship goods via LTL, the carrier uses the NMFC code to understand exactly what you're shipping and how to price it appropriately.
NMFC codes typically consist of 5-6 digits, sometimes followed by a sub-code. For example:
- NMFC 116030 - Machinery, NOI (Not Otherwise Indexed)
- NMFC 100240-02 - Household goods, packed, Class 100
- NMFC 61780 - Electronic equipment, NOI
About the NMFTA
The National Motor Freight Traffic Association (NMFTA) is the organization responsible for maintaining and publishing the National Motor Freight Classification. Founded in 1956, the NMFTA is a nonprofit membership organization that serves the motor carrier industry.
Key responsibilities of the NMFTA include:
- Publishing the NMFC tariff - The official classification document updated quarterly
- Assigning new NMFC codes - As new products enter the market
- Managing the SCAC system - Standard Carrier Alpha Codes for carrier identification
- Handling classification disputes - When shippers disagree with assigned classes
The NMFC is updated three times per year (typically in January, April, and August), with changes published in supplements. These updates may include new codes, modified classifications, or clarifications to existing entries.
The 18 Freight Classes Explained
Freight classes range from Class 50 (the lowest and least expensive to ship) to Class 500 (the highest and most expensive). The class assigned to your freight is primarily based on density, but also considers handling, stowability, and liability factors.
| Freight Class | Density (lbs/ft³) | Examples |
|---|---|---|
| Class 50 | 50+ lbs/ft³ | Sand, bricks, cement |
| Class 55 | 35-50 lbs/ft³ | Bricks, hardwood flooring |
| Class 60 | 30-35 lbs/ft³ | Car accessories, steel cables |
| Class 65 | 22.5-30 lbs/ft³ | Bottled beverages, books |
| Class 70 | 15-22.5 lbs/ft³ | Auto engines, food items |
| Class 77.5 | 13.5-15 lbs/ft³ | Tires, bathroom fixtures |
| Class 85 | 12-13.5 lbs/ft³ | Crated machinery |
| Class 92.5 | 10.5-12 lbs/ft³ | Computers, refrigerators |
| Class 100 | 9-10.5 lbs/ft³ | Boat covers, wine cases |
| Class 110 | 8-9 lbs/ft³ | Cabinets, framed artwork |
| Class 125 | 7-8 lbs/ft³ | Small appliances |
| Class 150 | 6-7 lbs/ft³ | Auto sheet metal, bookcases |
| Class 175 | 5-6 lbs/ft³ | Clothing, couches |
| Class 200 | 4-5 lbs/ft³ | Aircraft parts, mattresses |
| Class 250 | 3-4 lbs/ft³ | Bamboo furniture, plasma TVs |
| Class 300 | 2-3 lbs/ft³ | Wood cabinets, model boats |
| Class 400 | 1-2 lbs/ft³ | Deer antlers |
| Class 500 | <1 lb/ft³ | Ping pong balls |
The Four Classification Factors
The NMFTA uses four primary factors to determine freight classification:
1. Density
Density is calculated as weight divided by volume (pounds per cubic foot). This is typically the most important factor.
Density Calculation Example
A shipment weighs 500 lbs and measures 48" x 40" x 48"
Step 1: Calculate cubic feet: (48 × 40 × 48) ÷ 1,728 = 53.33 cubic feet
Step 2: Calculate density: 500 ÷ 53.33 = 9.38 lbs/ft³
Result: This density falls within Class 100 (9-10.5 lbs/ft³)
2. Stowability
How easily freight can be arranged with other cargo. Irregular shapes, hazardous materials, or items that can't be stacked affect this.
3. Handling
The care and effort required to move freight. Fragile items, temperature-controlled goods, or oversized items require special handling.
4. Liability
The probability of damage, theft, or causing damage to other freight. High-value items and perishables have higher liability.
How to Find Your NMFC Code
Finding the correct NMFC code is critical for accurate pricing:
Method 1: Use Our Free Database
The fastest way is to search our database of 6,609+ codes by product description, Article ID, or category.
Method 2: Contact Your Carrier
LTL carriers have access to the official NMFC tariff and can help identify the correct code.
Method 3: Use the Official NMFC Tariff
The NMFTA publishes the official tariff, available through subscription.
How to Read NMFC Codes
NMFC Code Structure
Example: NMFC 100240-02
- 100240 - The base Article ID (identifies the commodity)
- -02 - The sub-code (specifies a variation or packing method)
How to Reduce Shipping Costs
1. Optimize Your Packaging
Reducing dimensions increases density, potentially lowering your freight class. Use smaller boxes, remove excessive padding, and consider disassembling items.
2. Verify Your Classification
Ensure you're using the most specific code available. Check for sub-codes that may offer better rates.
3. Consider FAK Agreements
High-volume shippers can negotiate FAK (Freight All Kinds) agreements with carriers for a single freight class on all shipments.
4. Consolidate Shipments
Combining smaller shipments improves overall density and may qualify for volume discounts.
Common Classification Mistakes
- Using Outdated Codes - The NMFC updates three times per year
- Incorrect Measurements - Measure accurately, including packaging and pallets
- Using Generic "NOI" Codes - A more specific code may have a better classification
- Ignoring Packaging Requirements - Many codes specify packaging requirements
- Miscounting Pieces - Each handling unit should be counted separately
Frequently Asked Questions
What happens if I use the wrong NMFC code?
Carriers will reclassify your shipment and adjust your invoice, usually resulting in a higher freight bill plus potential reclassification fees.
Can I appeal a freight classification?
Yes, you can file a petition with the NMFTA's Classification board with detailed product information.
How often do NMFC codes change?
The NMFTA publishes updates three times per year, typically in January, April, and August.
Is NMFC classification required for all shipments?
NMFC classification is specifically for LTL shipments. FTL, parcel, and international shipments may use different systems.
- The NMFC Codes Team
December 19, 2025