How is freight density calculated?

Multiply length, width and height in inches to get cubic inches, divide by 1,728 to get cubic feet, then divide the weight in pounds by the cubic feet. A 48 by 40 by 48 inch pallet weighing 500 pounds is 53.3 cubic feet, so its density is 9.4 pounds per cubic foot.

Why does my carrier's class differ?

This calculator estimates the class from density alone. Some items have a specific class in the NMFC that overrides density, and the carrier or the NMFC decides the final class. Carriers can also re-measure and re-weigh a shipment and reclassify it.

Freight class calculator

A freight class calculator works out the density of your shipment and gives an estimated freight class for LTL shipping. Density = total weight in pounds ÷ total volume in cubic feet. The class comes from the density table on this page.

Enter the length, width, height and weight of each piece. This free calculator is an estimate by density. Some items have a set class in the NMFC, and your carrier confirms the final class. No signup.

Formula: Density = total weight in lbs ÷ total volume in cubic feet, where volume = length × width × height in inches ÷ 1,728
Example: One piece 48 × 40 × 48 in at 500 lbs is 53.3 cubic feet and 9.4 lbs per cubic foot
Class table: NMFTA, National Motor Freight Classification (NMFC) density-based classification, effective July 19, 2025
Last updated: October 14, 2026

Units

Enter your freight in inches and pounds, or in centimeters and kilograms. The result is the same for the same shipment.

Units

Piece line 1

Dimensions and weight of one piece, and how many pieces are the same.

Length

Width

Height

Weight per piece

lbs

Number of pieces

Fill in the required details above to see your results.

Freight Class Calculator

We work out your freight's density from its size and weight, then look up the estimated class. Enter your numbers on the left to see it.

Enter length, width, height, weight and number of pieces for every line to see the density.

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Density to class table

Source: NMFTA, National Motor Freight Classification (NMFC) density-based classification, effective July 19, 2025. This table is being checked against the source.

Density in pounds per cubic foot and the estimated freight class
Density (lbs per cubic foot)	Estimated class
50 or more	50
35 but less than 50	55
30 but less than 35	60
22.5 but less than 30	65
15 but less than 22.5	70
12 but less than 15	85
10 but less than 12	92.5
8 but less than 10	100
6 but less than 8	125
4 but less than 6	175
2 but less than 4	250
1 but less than 2	300
Under 1	400

How to use the freight class calculator

Measure each piece with its pallet and have the weights ready.

Choose your units
Pick inches and pounds, or centimeters and kilograms. The result is the same for the same shipment.
Enter size and weight
For each piece, type the length, width and height including the pallet, and the weight per piece.
Add the number of pieces
Set how many pieces share those dimensions. Use Add another line for pieces of a different size or weight.
Read the density and class
See the total volume, total weight, density and the estimated class from the density table below the calculator.
Confirm with your carrier
The class is an estimate by density. Some items have a set NMFC class, and your carrier confirms the final class.

How freight class works

LTL carriers price a shipment partly by its freight class. Class comes from the National Motor Freight Classification (NMFC), published by the NMFTA, and is based on density, stowability, handling and liability. Dense, compact freight gets a lower class and a lower rate. Light, bulky freight gets a higher class.

The NMFTA moved to a density based system for many items, effective July 19, 2025. This calculator finds your density and looks up the class for that density in the table on this page.

How freight density is calculated

Measure each piece including the pallet, then work through these steps.

Multiply length × width × height in inches to get cubic inches.
Divide by 1,728 to get cubic feet, then multiply by the number of pieces.
Divide the total weight in pounds by the total cubic feet.
Example: 48 × 40 × 48 = 92,160 cubic inches ÷ 1,728 = 53.3 cubic feet. 500 lbs ÷ 53.3 = 9.4 lbs per cubic foot.

Why your carrier's class can differ

The result here is an estimate by density. Some items have a set NMFC class that overrides density, and the carrier or the NMFC decides the final class. Carriers can also re-measure and re-weigh a shipment and reclassify it.

FAQ'sFrequently Asked Questions

Freight class is a number from 50 to 500 that the National Motor Freight Classification (NMFC) gives to freight shipped by LTL carriers. It reflects how costly the freight is to move, based on density, handling, stowability and liability. A lower class generally means a lower rate.

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