Freight class calculator: density to NMFC class

LTL carriers price by freight class, and for most freight the class comes from density — pounds per cubic foot. Enter your handling units and the calculator works out the density and the class on the current NMFC scale. Inches and pounds, free, no sign-up.

How the math works

Three steps, and the calculator does all of them. Multiply length by width by height in inches and divide by 1,728 to get cubic feet. Divide total pounds by cubic feet to get density. Look that density up on the scale.

A pallet 48 by 40 by 48 inches is 92,160 cubic inches, which is 53.3 cubic feet. At 500 pounds that is 9.4 pounds per cubic foot, which lands at class 100. The same pallet at 160 pounds is 3 pounds per cubic foot — class 250, and a much higher rate for freight that weighs a third as much.

The scale changed in 2025

The density scale used to collapse everything at 30 pounds per cubic foot and above into class 60, so genuinely heavy freight had nowhere lower to go. The 2025 revision added breaks at 35 and 50, which brought classes 55 and 50 into the density scale.

It cuts both ways. Dense, well-packed freight now reaches a lower class than it could before. Light freight that fills a pallet footprint tends to land higher than it used to. If you have not re-run your regular lanes since the change, it is worth doing.

Many freight class calculators online still show the old eighteen-step table with 77.5, 110, 150, 200 and 500 in the density column. Those classes still exist, but they come from commodity-specific item numbers now, not from density.

When density is not the answer

Density sets the class for most freight, but not all of it. A commodity with its own NMFC item number carries that class regardless of how dense it is. Three other factors can also move it:

Stowability. Odd shapes, hazardous materials and anything that cannot be loaded next to other freight push the class up.

Handling. Freight that needs special equipment or extra care costs more to move. Standard cartons on a standard pallet score well here.

Liability. High value, fragile or theft-prone goods carry more risk for the carrier and can be classed higher than density alone would suggest.

So treat the number here as the density-based estimate it is. Before you quote a customer, check whether your commodity has its own item number.

Measuring it right

Carriers dimension what arrives on their dock. Measure the handling unit as it ships: packaged, palletized, to the outermost points including any overhang. A product spec sheet will understate the size, because it ignores the carton, the dunnage and the pallet.

This is where most reclassification bills come from. The freight measures bigger than the paperwork said, density drops, class goes up, and the carrier rebills the difference.

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