Freight class is a standardized classification system used in the shipping industry to determine the cost of transporting goods. Developed by the National Motor Freight Traffic Association (NMFTA) in the U.S., freight class helps carriers, shippers, and logistics providers establish pricing, ensure proper handling, and optimize transportation efficiency.
This guide will explain what freight class is, why it matters, and how to determine it for your shipments.
What is Freight Class?
Freight class is a rating assigned to Less-Than-Truckload (LTL) shipments based on their characteristics. The National Motor Freight Classification (NMFC) system categorizes goods into 18 different classes, ranging from Class 50 (least expensive) to Class 500 (most expensive). The classification depends on several key factors that affect shipping costs and logistics.
Why is Freight Class Important?
- Determines Shipping Costs – Higher freight class means higher costs due to increased handling difficulty and space requirements.
- Affects Carrier Selection – Carriers use freight class to determine capacity, pricing, and service requirements.
- Ensures Compliance – Proper classification helps avoid additional charges, reclassification fees, and shipping delays.
- Standardizes Pricing Across the Industry – Freight class provides a uniform system for determining rates, making logistics planning easier.
Key Factors in Determining Freight Class
Freight class is determined by four main factors:
1. Density (Weight-to-Volume Ratio)
- Formula: Density = Weight (lbs) ÷ Volume (cubic feet)
- Higher density = Lower freight class (cheaper to ship)
- Lower density = Higher freight class (more expensive)
- Example: A compact, heavy item like steel bars has a low class, while a bulky, lightweight item like foam has a high class.
2. Stowability (Ease of Storage and Handling)
- Items that are irregularly shaped, hazardous, or require special storage may have a higher freight class.
- Example: Stackable boxes have a lower freight class than oddly shaped machinery requiring special handling.
3. Handling (Ease of Loading and Transporting)
- Freight that requires special equipment (e.g., forklifts, cranes) or manual handling increases classification.
- Fragile or hazardous items also fall into a higher class due to additional handling precautions.
4. Liability (Risk of Damage or Theft)
- High-value, perishable, or easily damaged items may fall into a higher freight class due to insurance risks.
- Example: Electronics and glassware have a higher class than durable materials like bricks.
Freight Class Chart (Examples)
| Freight Class | Example Items | Density Range (lbs/cubic ft) |
|---|---|---|
| 50 | Steel rods, bricks | 50+ |
| 55 | Hardwood flooring, car engines | 35-50 |
| 60 | Car parts, canned food | 30-35 |
| 70 | Machinery, books | 22.5-30 |
| 85 | Tires, furniture pieces | 15-22.5 |
| 100 | Clothing, plastic products | 10-15 |
| 125 | Bicycles, home appliances | 8-10 |
| 150 | Mattresses, lightweight metal furniture | 6-8 |
| 175 | Sofas, wooden furniture | 4-6 |
| 200 | Bags of chips, insulation | 3-4 |
| 250 | Large plastic tanks, foam products | 2-3 |
| 300 | Ping pong balls, empty bottles | 1-2 |
| 400-500 | Feather pillows, balloons | <1 |
How to Determine Freight Class
Step 1: Measure the Shipment Dimensions
Use a measuring tape to get the length, width, and height of your packaged shipment in inches.
Step 2: Convert to Cubic Feet
Multiply the dimensions (L × W × H in inches) and divide by 1,728 (the number of cubic inches in a cubic foot).
Formula:
Cubic Feet = (Length × Width × Height) ÷ 1,728Step 3: Weigh the Shipment
Use a scale to determine the total weight in pounds.
Step 4: Calculate the Density
Use the density formula:
Density = Weight (lbs) ÷ Volume (cubic feet)Step 5: Compare with Freight Class Chart
Match your shipment’s density to the NMFC chart to determine the correct freight class.
Common Mistakes to Avoid
- Misreporting Dimensions or Weight – Carriers reweigh shipments and charge reclassification fees for inaccurate data.
- Not Accounting for Packaging – Always measure the final, packaged dimensions, not just the product size.
- Ignoring Special Handling Needs – If your shipment requires special storage, it may belong to a higher class.
- Assuming Freight Class is Fixed – Freight class can change based on packaging, stacking ability, and handling method.
Tools for Freight Class Calculation
To simplify the process, consider using:
- Online Freight Class Calculators – Many carriers and third-party logistics (3PL) providers offer online tools.
- Freight Classification Experts – Working with a shipping broker or freight expert can prevent costly misclassifications.
- NMFC Database Access – Businesses can subscribe to the NMFTA database for precise NMFC codes and freight classes.
Conclusion
Understanding freight class is essential for accurate shipping cost estimation, smoother logistics operations, and compliance with carrier regulations. By considering factors like density, stowability, handling, and liability, businesses can ensure proper classification, avoid extra fees, and optimize their freight shipping process.
By following the steps outlined above, shippers can efficiently determine freight class, make informed decisions, and reduce overall transportation costs. Investing in proper measurement tools and consulting with experts can further streamline the process.
