Freight density (PCF) and NMFC freight class explained

In US LTL shipping, the denser your freight, the lower its class and usually the lower the rate. Here is how to calculate density and what the current scale says.

Updated October 2026

What is freight density?

Freight density is weight divided by volume, measured in pounds per cubic foot (PCF). Carriers use it because a light, bulky pallet takes as much trailer space as a heavy one but pays less if charged on weight alone.

How to calculate PCF

1. Measure the shipment as it will travel, including the pallet, in inches: length × width × height. Measure to the outermost points, including any overhang.
2. Work out the volume in cubic feet: L × W × H ÷ 1,728.
3. Divide the total weight in pounds, including the pallet, by the cubic feet.

Example: a 48 × 40 in pallet loaded to 60 in high, weighing 900 lb in total. Volume: 48 × 40 × 60 ÷ 1,728 = 66.7 cu ft. Density: 900 ÷ 66.7 = 13.5 PCF, which falls in the 12 to under 15 band: class 85.

Working in metric? Density in kg/m³ × 0.0624 gives lb/ft³.

The NMFC density scale (since July 2025)

On 19 July 2025 the National Motor Freight Classification moved to a 13-tier standard density scale (NMFTA Docket 2025-1), replacing the old 11 tiers and adding classes 55 and 50 for dense freight. Many commodities are now classed by density alone.

This is the standard density scale. The class that applies to your shipment depends on its NMFC item: some commodities have their own classes or adjustments for handling, stowability and liability. Check the NMFC item or ask your carrier before you rely on a class.

Avoiding re-class and re-weigh charges

• Measure the real shipment, not the box sizes on paper. Shrink wrap, top caps and pallets all add size.
• Stop overhang. A box sticking out past the pallet edge increases the measured volume, lowers density and can push you into a higher class.
• Build square, flat-topped loads. Carriers often treat a pallet as unstackable if the top is uneven, and measure the space it takes.
• Keep the class on the bill of lading accurate. Carriers inspect, re-measure and re-class shipments, and charge the difference.

Let PalletBrain do the maths

When you work in inches and pounds, PalletBrain Pro and Team show the PCF and an estimated class for every pallet in your load plan, and flag any overhang, so you can fix a load before it ships. Start with the free pallet calculator.