LTL freight class is driven largely by density — pounds per cubic foot. Higher density usually means a lower (cheaper) class. Density is weight over cubic feet.
The example
150 lb, 48×40×48 in.
| A | B | |
|---|---|---|
| 1 | Item | Value |
| 2 | 92,160 / 1728 | 53.3 cu ft |
| 3 | 150 / 53.3 | → ~2.8 lb/ft³ |
The formula
The formula:
How it works
How it works:
- Cubic feet = (L × W × H in inches) ÷ 1,728.
- Divide weight by cubic feet for density (lb/ft³).
- Higher density → lower freight class → cheaper rate (denser freight ships efficiently).
- Map density to a class table with a lookup if you need the NMFC class number.
Density rewards packing tight. LTL classes run from 50 (dense, cheap) to 500 (light, bulky, expensive), and density is the main driver: a denser shipment occupies less trailer per pound, so it costs less to haul. Computing lb/ft³ before booking lets you see your likely class — and shows when consolidating or re-packing to raise density would drop you into a cheaper class.
Try it: interactive demo
Weight and dimensions (in).
Variations
Cubic feet
From inches:
Class lookup
Density to class:
Pallets of cube
Trailer fit:
Pitfalls & errors
1,728. Cubic inches ÷ 1,728 = cubic feet.
Density ≠ class exactly. Class also weighs handling, stowability, liability.
Zero volume. Bad dimensions give #DIV/0!.
Practice workbook
Frequently asked questions
How do I calculate freight density in Excel?
How does density affect freight class?
How do I map density to a class?
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