Logistics Freight Class Calculator

Density, Not Weight Alone, Sets the Price of an LTL Shipment

Less-than-truckload carriers don't price freight purely by the pound — a pallet of pillows and a pallet of steel brackets can weigh the same but cost very different amounts to move, because the pillows eat up trailer space the carrier could otherwise sell to another shipper. The National Motor Freight Classification (NMFC) system solves this by assigning a freight class based primarily on density, from Class 50 (very dense, cheap to ship) to Class 500 (very light and bulky, expensive to ship).

The Formula

Volume (ft³) = (Length × Width × Height) / 1728
Density (lb/ft³) = Weight / Volume
Freight Class = NMFC density lookup

Length, width, and height are entered in inches, so dividing by 1,728 (the number of cubic inches in a cubic foot) converts the volume to cubic feet before density is calculated. The resulting density in pounds per cubic foot is then matched against the standard density brackets below.

Standard Density-to-Class Table

NMFC-style freight class by density (representative brackets)
Density (lb/ft³)Freight class
50 or moreClass 50
22.5 – 29.9Class 65
15 – 22.4Class 70
9 – 10.4Class 100
4 – 4.9Class 200
2 – 2.9Class 300
Under 1Class 500

A 150 lb pallet measuring 48 × 40 × 48 in has a volume of 53.33 ft³ and a density of 2.81 lb/ft³ — Class 300, a common bracket for palletized but lightweight consumer goods.

Note: this is a density-based estimate. Actual NMFC classification also weighs stowability, handling difficulty, and liability, and should be confirmed against your bill of lading and carrier's tariff before shipping.

How to Use This Calculator

  1. Enter the shipment's Weight in pounds.
  2. Enter Length, Width, and Height in inches.
  3. Select Calculate to get the cargo density and the estimated freight class.

Related Calculations

Once you have a class, get a rate estimate with the Freight Cost Calculator, or compare against parcel dimensional weight rules with the Dimensional Weight Calculator.