What is NMFC freight class?

The National Motor Freight Classification assigns every LTL commodity a class from 50 to 500 based on four factors: density, stowability, handling, and liability. The class is the main driver of an LTL freight rate alongside weight and distance.

How is density calculated?

Density is the shipment weight in pounds divided by its total volume in cubic feet (PCF). A pallet 48 by 40 by 48 inches is 53.3 cubic feet, so a 300 lb load on it is about 5.6 PCF.

Does density alone set the class?

For many commodities yes, but stowability, handling, and liability can override it. Hazardous, fragile, or high-value goods classify higher than their density suggests, which this tool reflects by bumping the class up.

Why does a higher class cost more?

Higher classes (lower density, harder to handle, higher liability) take more trailer space and risk per pound, so carriers charge more. Denser, easier freight sits in lower classes and ships cheaper.

Is this an official NMFC lookup?

No. It uses the standard density scale and factor adjustments to estimate the class. Some commodities have a fixed NMFC item number that supersedes density, so confirm against the official NMFC book before billing.

Freight Class (NMFC) Calculator

LTL carriers price freight by its NMFC class, and the class hinges first on density — how many pounds you pack into each cubic foot. This calculator works out your shipment’s density, maps it to the standard class scale, then adjusts for the three non-density factors that can push a commodity into a higher class.

How it works

Freight class is set by four factors. Density is computed directly:

volume (ft³) = length × width × height / 1728   (inches)
density PCF  = weight (lb) / volume (ft³)

The PCF value is matched against the standard density table: 50 PCF or more is class 50, around 5.6 PCF is class 150, and under 1 PCF is class 400 or 500. Lower density means a higher class. The other three factors then adjust it:

Stowability — odd shapes, hazmat, or items that cannot be stacked classify higher.
Handling — fragile or special-care freight classifies higher.
Liability — high-value or perishable goods classify higher.

Each adverse factor bumps the class up one or more steps on the class scale.

Example and tips

A standard pallet measuring 48 by 40 by 48 inches holds 53.3 cubic feet. A 300-pound load on it gives about 5.6 PCF, which maps to class 150. If the same freight were fragile and high-value, the tool would step it up to class 175 or 200. To lower your class and your bill, pack denser: the single biggest lever is fitting more weight into the same footprint. Always verify against the official NMFC item number for your commodity, since some products carry a fixed class regardless of density.