NMFC Freight Class & Density Calculator
Results
Estimated Density: lbs/cu ft
Estimated Freight Class:
*Note: Final NMFC classification depends on stowability, handling, and liability, not just density.
Understanding NMFC Numbers and Freight Classification
The National Motor Freight Classification (NMFC) is a standard used by the shipping industry to categorize commodities based on their "transportability." This system, managed by the National Motor Freight Traffic Association (NMFTA), ensures that shippers and carriers have a uniform basis for negotiating freight rates.
How is an NMFC Class Calculated?
While many factors contribute to a freight class, density is often the primary driver for "density-based" items. Our NMFC number calculator uses the industry-standard formula to determine the pounds per cubic foot (PCF):
- Step 1: Multiply Length x Width x Height in inches to get total cubic inches.
- Step 2: Divide the cubic inches by 1,728 to convert to cubic feet.
- Step 3: Divide the weight of the shipment (in lbs) by the total cubic feet.
The Four Transportation Characteristics
An NMFC number isn't just about size; it evaluates four specific metrics:
- Density: The weight per cubic foot. Higher density usually results in a lower class and lower cost.
- Stowability: How easily the freight can be stacked or stored in a trailer. Hazardous or oddly shaped items may be classed higher.
- Handling: The degree of care needed. Fragile or difficult-to-move items increase the classification.
- Liability: The value of the goods and their susceptibility to theft, damage, or breakage.
Standard NMFC Density Chart
| Density (lbs per cubic foot) | Estimated Class |
|---|---|
| Over 50 | 50 |
| 15 to 22.5 | 70 |
| 10.5 to 12 | 92.5 |
| 8 to 9 | 110 |
| Less than 1 | 500 |
Practical Example
Imagine you are shipping a pallet of heavy machinery parts. The pallet is 48″L x 40″W x 30″H and weighs 800 lbs.
- Cubic Inches: 48 x 40 x 30 = 57,600
- Cubic Feet: 57,600 / 1728 = 33.33 cu ft
- Density: 800 / 33.33 = 24.00 PCF
- Result: At 24 PCF, this item would typically fall into Class 65.
Important Tip: Always round your measurements up to the nearest inch and weight up to the nearest pound to avoid "re-weigh" fees from carriers. Using an accurate NMFC number calculator helps prevent unexpected freight bill audits.