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Freight Class Calculator

Work out the density of an LTL shipment in pounds per cubic foot and the freight class it suggests, from the pallet’s size, weight and number of pieces.

Results

ItemValue
Measure the outside of the shipment as it will ship, including the pallet, and round each size up to the next whole inch. Density is only one factor: the class an item actually takes is set by its NMFC item, and handling, stowability and liability can change it. Check with your carrier.

Quick Answer

Freight class from density = total weight in pounds ÷ total volume in cubic feet, then read the class from the NMFTA density table. A 48 × 40 × 48 inch pallet weighing 500 lb is 53.33 cubic feet, so its density is 9.38 lb per cubic foot, which falls in class 100. Lighter, bulkier freight gets a higher class and usually costs more to ship per pound.

Last updated: 10 November 2026 ·How we calculate this: density in pounds per cubic foot and the NMFTA density guidelines

How This Freight Class Calculator Works

Less-than-truckload (LTL) carriers in the US price shipments partly by freight class, a number from 50 to 500 in the National Motor Freight Classification (NMFC). Enter the size and weight of one piece, such as a pallet, and how many identical pieces there are. The calculator finds the total cubic feet, the density in pounds per cubic foot, and the class that density matches in the density guidelines published by the National Motor Freight Traffic Association (NMFTA).

Quick explanation: the denser the freight, the lower the class.

  • Class 50: very dense freight, 50 lb or more per cubic foot.
  • Class 500: very light freight, under 1 lb per cubic foot.
  • Lower class usually means a lower rate per pound.

How to Use the Freight Class Calculator

  1. Choose inches and pounds, or centimeters and kilograms.
  2. Enter the length, width and height of one piece as it will ship.
  3. Enter the weight of one piece, including the pallet.
  4. Enter how many identical pieces there are.
  5. Press Calculate to see the density and suggested class.

Freight Density Formulas

  • Cubic feet of one piece: length × width × height (inches) ÷ 1,728
  • Total cubic feet: cubic feet per piece × number of pieces
  • Density: total weight (lb) ÷ total cubic feet
  • Class: the row in the density table whose minimum density your shipment meets

Key Terms

  • LTL: less-than-truckload: freight that fills only part of a trailer and shares it with other shipments.
  • NMFC: the National Motor Freight Classification, the standard that sets freight classes.
  • NMFTA: the National Motor Freight Traffic Association, which publishes the NMFC.
  • Density: weight per unit of volume, here pounds per cubic foot.
  • Re-class: when a carrier changes the class of a shipment after inspection, often with a fee.

Worked Example

You ship two pallets of lamps, each 48 × 40 × 60 inches and 150 lb.

  • Cubic feet per pallet = 48 × 40 × 60 ÷ 1,728 = 66.67
  • Total = 133.33 cubic feet; total weight = 300 lb
  • Density = 300 ÷ 133.33 = 2.25 lb per cubic foot
  • That falls between 2 and 3 lb per cubic foot, so the density table gives class 300.

Real-Life Examples

  • Standard pallet: 48 × 40 × 48 in at 500 lb is 9.38 lb/cu ft, class 100.
  • Heavy machine parts: 40 × 48 × 36 in at 1,200 lb is 30.00 lb/cu ft, class 60.
  • Bulky lamps: two 48 × 40 × 60 in pallets at 150 lb each are 2.25 lb/cu ft, class 300.
  • Repacking: cutting the 500 lb pallet to 40 in high raises density to 11.25, class 92.5.

Freight Class vs Dimensional Weight

  • Freight class: used by LTL carriers for palletized freight, based on density and other traits.
  • Dimensional (DIM) weight: used by parcel carriers, which charge the higher of actual weight or size ÷ a divisor.
  • Both charge more for light, bulky shipments.

Freight Class Density Table

From the NMFTA Freight Classification Development Council density guidelines.

Minimum density (lb per cu ft)Class
5050
3555
3060
22.565
1570
13.577.5
1285
10.592.5
9100
8110
7125
6150
5175
4200
3250
2300
1400
Less than 1500

Density Is Not the Whole Story

NMFTA notes that its density guidelines assume no unusual or significant handling, stowability or liability characteristics. Fragile, hazardous, oddly shaped or very valuable items may be classed higher than their density suggests. Many products have their own NMFC item number with a fixed class or a density scale. Ask your carrier or check the NMFC to confirm the class, because a wrong class can lead to a re-class fee and a higher bill.

You can often lower the class by packing more tightly: smaller boxes, less empty space on the pallet, or stacking to a consistent height.

Common Mistakes to Avoid

  • Leaving out the pallet. Include its height and weight.
  • Measuring the product, not the shipment. Measure the outside of the wrapped pallet.
  • Not rounding up. Carriers round each size up to the next inch.
  • Assuming density decides everything. Many items have a fixed NMFC class.
  • Mixing units. Use inches with pounds, or centimeters with kilograms.

Frequently Asked Questions

Work out density (pounds ÷ cubic feet) and look it up in the density table. Then check the product’s NMFC item.

The weight of a shipment divided by its volume, in pounds per cubic foot.

It depends on its weight and height. A 48 × 40 × 48 in pallet at 500 lb is about 9.4 lb/cu ft, class 100.

Class 50, for freight of 50 lb or more per cubic foot.

Class 500, for freight under 1 lb per cubic foot.

Usually, yes. Lower classes have lower rates per hundred pounds.

The NMFTA publishes the National Motor Freight Classification.

Yes. The calculator converts them to inches and pounds.

The carrier measured a different size or weight, or the item has its own NMFC class.

References & Sources

SourceUsed ForLink
NMFTA, Freight Classification Development Council Density Guidelines Minimum average density for each freight class. https://nmfta.org/wp-content/uploads/2026/02/FCDC-Density-Guidelines-1.pdf
NMFTA, National Motor Freight Classification What the NMFC is and its classes from 50 to 500. https://nmfta.org/standards/classification/nmfc/