Freight Class After the NMFC Rewrite: Density Decides It

Freight classification used to be a lookup: you found your commodity in a published listing, read off the class, and put it on the bill of lading.

For most shipments it is now a calculation. The National Motor Freight Traffic Association moved the classification to a density-based structure in July 2025. The consequence is practical rather than theoretical: the number on the paperwork comes from a tape measure and a scale in your own warehouse.

This reference covers what changed, how the density calculation works, the measurement error that costs the most money, and what to watch as further revisions land.

What Changed in July 2025

The NMFTA calls the program Classification Reimagined, and the first phase took effect on July 19, 2025 under Docket 2025-1. The NMFTA folded more than two thousand listings into a density model.

The density scale itself grew from eleven tiers to thirteen, with classes added at the dense end. Finer tiers mean a given pallet lands closer to the class its density actually warrants, rather than being swept into a broad band.

Classification still rests on four characteristics: density, stowability, handling and liability. What changed is their weighting. Freight with no special stowability, handling or liability concerns is now classified on density alone, and new symbols flag the items where the other three still apply.

For ordinary boxed or palletized goods, that covers most of what moves. The commodity description stopped being the thing that decides the rate.

How the Calculation Works

Density is weight divided by volume, in pounds per cubic foot. Measure the length, width and height of the shipment in inches, multiply them, and divide by 1,728 for cubic feet, then divide the weight by that figure.

A pallet measuring 48 by 40 by 30 inches occupies 33.33 cubic feet, so at 900 lb it works out at 27 PCF.

Denser freight takes a lower class, and a lower class costs less. That relationship is worth holding onto, because it explains why measurement errors run in one direction.

The Error That Costs Money

Work the density on the shipment exactly as you hand it to the carrier. That means the pallet, the packaging, the stretch wrap and anything else riding along.

Leaving the pallet out is the common mistake, and it runs the wrong way. Dropping the pallet removes about five and a half inches of height and forty pounds or so of weight. Losing the height shrinks the volume faster than losing the weight shrinks the weight, so the freight looks denser than it is.

Denser means a lower class, and a lower class means a rate the shipment was never entitled to. Carriers weigh and dimension freight in their terminals, so the correction arrives as a reclassification charge on the invoice.

Overhang deserves the same care, because if the load extends past the pallet edge the measurement follows the load rather than the deck. The trailer space consumed follows the load too.

What the Change Actually Cost

The move was a restructuring rather than a price rise, and the measured effect bears that out fairly clearly. One rating provider re-rated historical shipments against the new scale and reported swings of roughly two to three percent in either direction, depending on the freight profile.

That is small in aggregate and large for particular products. A shipper whose goods sat in a broad commodity band may find them landing in a tighter density tier that fits better, for better or worse. Dense, compact freight generally did well out of the added tiers at the bottom of the range.

The sensible response is to re-rate your own history rather than assume the direction. A provider with your shipment data can do it in an afternoon, and the answer is specific to what you ship.

Where the Bands Are

The thirteen tiers and their breakpoints live in the published classification, which the NMFTA distributes by subscription. They are not reproduced here, and any table that promises the whole scale for free is worth treating carefully.

The shape is easy enough to hold without the exact numbers. Very light freight sits at the top of the range, near class 500. Very dense freight sits at the bottom, at class 50. Everything else falls between, and the tiers narrow as density rises.

What matters day to day is knowing your density to one decimal place. Check that against the current scale, rather than against a class someone quoted you in a previous year.

When Density Is Not the Whole Answer

Some freight still resists the model. Goods that are awkward to stow, need special handling, or carry unusual liability keep those characteristics in the reckoning, and new symbols mark them in the classification.

Where a commodity genuinely does not fit, the NMFTA runs an interpretations team that will rule on it, alongside an item lookup tool for checking whether a particular listing moved. Those are better first stops than guessing at a class and discovering the answer on an invoice.

Classification also stops at the border. NMFC codes apply across the United States, Canada and Mexico, while customs uses harmonized system codes for international shipments. The two systems answer different questions and do not substitute for one another.

This Is Not the Same as Dimensional Weight

Parcel carriers also price by cube, which is what dimensional weight measures, and the two systems get confused because both punish light bulky freight. The arithmetic is different, and so is the direction.

Dimensional weight converts volume into a billable weight and charges the greater of that and the scale weight. Freight class converts density into a class, and the class selects a rate per hundredweight.

One raises the weight you pay on. The other changes which rate table applies. A pallet that rates well under LTL can still be an expensive parcel shipment, and the reverse happens too.

The Scale Keeps Moving

Docket 2025-1 was the first phase rather than the whole program. The NMFTA followed it with Docket 2025-2 in August 2025, and further revisions have continued into 2026.

A class verified two years ago may no longer describe the same freight. The NMFTA publishes an item lookup tool and maintains an interpretations team for commodities that do not fall neatly into the density model.

Anyone shipping LTL regularly should re-check classes on a schedule rather than treating them as settled, particularly for products that sat on a commodity listing before the change.

Common Questions

Classifying Under the New Structure

This reference has covered the move to density, the calculation behind a class, the measurement error that produces correction charges, and the fact that further revisions keep arriving. The structural point is that classification stopped being a lookup and became a measurement.

That change rewards shippers who measure carefully and penalizes those who carry forward a class from an old bill of lading. A tape measure, a scale and a habit of re-checking are now the whole discipline.