Why Freight Classification Matters
Every LTL (less-than-truckload) shipment in the United States is assigned a freight class that determines its shipping rate. Get it wrong, and you face reclassification charges — often 2-3 times your original quote — plus delay fees and administrative headaches.
The National Motor Freight Classification (NMFC) system assigns classes from 50 (cheapest) to 500 (most expensive) based on four factors: density, stowability, handling requirements, and liability.
The Four Classification Factors
1. Density (Most Important)
Density is weight divided by volume (pounds per cubic foot). It's the primary driver for most classifications.
| Density (PCF) | Typical Class | |---|---| | 50+ | 50 | | 35-50 | 55 | | 22.5-30 | 65 | | 15-22.5 | 70 | | 12-15 | 85 | | 9-12 | 100 | | 6-9 | 150 | | 4-6 | 200 | | Under 2 | 400-500 |
Pro tip: Use our freight class calculator to quickly determine your class based on dimensions and weight.
2. Stowability
How easily can the freight be arranged with other shipments? Irregularly shaped items, hazardous materials, or freight that can't be stacked scores worse on stowability.
3. Handling
Does the freight require special equipment, care, or handling procedures? Fragile, oversized, or oddly shaped items increase the handling factor.
4. Liability
What's the risk of damage, theft, or causing damage to adjacent freight? High-value or perishable goods carry higher liability scores.
Common Classification Mistakes
Guessing Instead of Measuring
Always measure and weigh your freight precisely. Carriers will re-measure at origin or destination, and if your declared dimensions are wrong, you'll be reclassified and recharged.
Ignoring Packaging in Dimensions
Your freight class is based on the total shipping dimensions — including pallets, crates, and packaging. A product that's Class 70 loose might be Class 100 when palletized due to the larger cubic footprint.
Using the Wrong NMFC Code
Many products have specific NMFC commodity codes that override density-based classification. Check the NMFC database for your exact product before defaulting to density alone.
Not Accounting for Mixed Freight
When shipping multiple commodities on one pallet, the highest class among them typically applies to the entire shipment. Plan your palletization accordingly.
How to Avoid Reclassification
Measure accurately. Use the longest, widest, and tallest points — including packaging.
Photograph your freight. Before it leaves your dock, photograph it with a tape measure visible. This protects you in disputes.
Use proper NMFC codes. Don't guess. Look up your exact commodity.
Match your BOL. Ensure your Bill of Lading matches your actual freight dimensions, weight, and class.
Consider density-based pricing. Many carriers now offer density-based programs that eliminate traditional class-based pricing. Ask your broker about this option.
Need help classifying a tricky shipment? Contact our team — we deal with classification questions daily and can help you get it right the first time.