Understanding how shipments are classified for less-than-truckload (LTL) freight is critical to getting accurate quotes and avoiding billing issues. This guide will help you estimate your shipment’s classification and reduce costly surprises using our free calculator and reference tools.
What Is Freight Class?
Freight class is a standardized system used to categorize less-than-truckload (LTL) shipments. It helps carriers determine shipping rates and is based on four key factors:
- Density – the weight of your freight relative to its size
- Stowability – how easily it can be stored and transported
- Handling – whether special care is needed during transit
- Liability – the risk of damage, theft, or other issues
The National Motor Freight Classification (NMFC) assigns a class ranging from Class 50 (least expensive) to Class 500 (most expensive). The higher the class, the more expensive it is to ship.
Why Accurate Classification Affects Shipping Costs
Errors in classification lead to more than just reclassification fees. They can result in:
- Unexpected reclassification fees
- Invoice disputes
- Shipment delays
- Strained relationships with carriers
- Budgeting issues across your supply chain
Carriers are strict about proper classification, and if the class listed on your bill of lading (BOL) doesn't match your actual freight characteristics, you could be billed at a higher rate—or see delivery delays. Accurately classifying your freight ensures smoother operations and helps you avoid billing issues, customer complaints, and margin loss.
How to Calculate Freight Class
To determine your freight class, you’ll need:
- The total weight of your shipment
- The length, width, and height of each pallet or unit
- The number of pallets or pieces
Start by calculating your freight density, which is the shipment’s weight divided by its cubic volume. If you need help calculating density, try our free freight density calculator.
Once you have the density, use the chart below to estimate your freight class.
Freight Class Chart
| Density (in lbs per cubic foot) | Freight Class |
| Less than 1 | 400 |
| 1 but less than 2 | 300 |
| 2 but less than 4 | 250 |
| 4 but less than 6 | 175 |
| 6 but less than 8 | 125 |
| 8 but less than 10 | 100 |
| 10 but less than 12 | 92.5 |
| 12 but less than 15 | 85 |
| 15 but less than 22.5 | 70 |
| 22.5 but less than 30 | 65 |
| Over 30 | 60 |
Keep in mind: while density is often the primary factor, some items may fall into a higher class due to handling, stowability, or liability risks.
Avoid Common Classification Mistakes
Even small errors in measurement or classification can cause issues. Here are some of the most common pitfalls:
- Using outdated or assumed freight classes
- Rounding up or down on dimensions
- Forgetting to include packaging or pallet weight
- Neglecting to consider liability or handling needs
FreightPlus can help review your freight documentation and classification process to identify gaps and prevent unnecessary costs.
2025 NMFC Changes
Starting July 2025, the NMFC system is introducing major changes that will impact how freight is classified and priced. These updates will:
- Remove outdated commodity-based classes
- Apply a standardized density scale for most freight
- Require more accurate dimensional data
- Increase carrier audits and billing scrutiny
If your team isn’t prepared, you may face higher freight costs, more reclass charges, and shipping delays.
Need Freight Class Help?
We’re already helping customers prepare and can do the same for you. Our team will review your shipment data, identify potential risks, and make sure everything aligns with current NMFC standards and the upcoming 2025 changes.
