Freight Class Calculator (US LTL)
Estimate the NMFC freight class of an LTL shipment from its density — the pounds per cubic foot that drive most class assignments.
US LTL freight class comes from density = weight (lb) ÷ volume (cubic feet), where cubic feet = (L × W × H in inches) ÷ 1728. A 48 × 40 × 48 in pallet at 500 lb is 53.33 ft³ → 9.375 lb/ft³ → class 100. Denser freight gets a lower, cheaper class (class 50 is lowest; class 500 is for the lightest, bulkiest goods).
How freight class is worked out
For most commodities, US LTL freight class follows density: weight ÷ volume in cubic feet. Higher density means a lower (cheaper) class. We compute the density and map it to the standard 18-step scale.
This is a density-based estimate. The official NMFC class can also depend on the commodity, stowability, handling and liability, and some items carry a fixed class regardless of density. Use it to sanity-check a quote, then confirm the NMFC item with your carrier.
Need the exact boundary? Browse the complete freight class guide from class 50 to 500.
Density-to-class table
| Density (lb/ft³) | Freight class |
|---|---|
| 50 and over | 50 |
| 35 – 50 | 55 |
| 30 – 35 | 60 |
| 22.5 – 30 | 65 |
| 15 – 22.5 | 70 |
| 13.5 – 15 | 77.5 |
| 12 – 13.5 | 85 |
| 10.5 – 12 | 92.5 |
| 9 – 10.5 | 100 |
| 8 – 9 | 110 |
| 7 – 8 | 125 |
| 6 – 7 | 150 |
| 5 – 6 | 175 |
| 4 – 5 | 200 |
| 3 – 4 | 250 |
| 2 – 3 | 300 |
| 1 – 2 | 400 |
| under 1 | 500 |
By carrier
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Frequently asked questions
How is freight class calculated?
For density-rated commodities, divide the shipment weight (lb) by its volume (cubic feet) to get density in lb/ft³, then read the class from the NMFC density scale. Denser freight gets a lower class number and a lower rate.
What is the lowest (cheapest) freight class?
Class 50 is the lowest and cheapest, for very dense freight of 50 lb/ft³ or more. The scale runs up to class 500 for very light, bulky goods under 1 lb/ft³.
Is density the only thing that sets freight class?
No. Many commodities are class-rated by their NMFC item number based on stowability, handling and liability as well as density. This calculator gives the density-based estimate, which is correct for a large share of general freight.