Freight class explained: what it means, how density sets it, and who decides yours

Freight class decides much of what an LTL shipment costs, and it's the line on a bill of lading most likely to be changed after pickup. This guide explains what freight class is, how density sets most classes, what changed in 2025, who actually decides your class, and how to avoid a reclass. It's written for shippers who want to get it right and for carriers who haul LTL-sized freight in a 26 ft box or a van and want to understand the numbers on the paperwork.

Try the visual guide below: change the pallet's size and weight and watch the density and the estimated band move. The ladder underneath is the public density scale.

What freight class is

The National Motor Freight Classification, published by the National Motor Freight Traffic Association (NMFTA), assigns every commodity a freight class from 50 to 500. Lower classes are for freight that's cheap to move per pound; higher classes for freight that's costly. Carriers don't price directly from the class. They apply it in their own tariffs, together with weight and distance, to set the rate.

Classes are assigned using four transportation characteristics: density, handling, stowability and liability. Density is weight relative to space. Handling is how easily the freight moves across a dock and in and out of a trailer. Stowability is how well it fits with other freight. Liability is how likely it is to be damaged, or to damage something else.

Sources: NMFTA, National Motor Freight Classification, checked October 2026; NMFTA, National Motor Freight Classification, checked October 2026

Freight class chart: the density scale

For many items, the NMFC says the class follows the density scale. Under the scale as publicly described for NMFC Docket 2025-1, which took effect on July 19, 2025, the 13 density bands run from class 50 for freight of 50 pounds per cubic foot and over, to class 400 for freight under 1 pound per cubic foot. The ladder in the visual guide shows every band.

Sources: NMFTA Docket 2025-1 (Disposition Bulletin 1371), as summarized publicly by carriers and brokers, checked October 2026; NMFTA Docket 2025-1, checked October 2026 Not all items use this scale; check your item.

Some examples from the scale, as density math only:

• Class 60 covers 30 to under 35 pounds per cubic foot: dense freight such as heavy cartons of liquids or metal parts, if the item uses the density scale.
• Class 70 covers 15 to under 22.5 pounds per cubic foot.
• Class 85 covers 12 to under 15 pounds per cubic foot.
• Class 125 covers 6 to under 8 pounds per cubic foot.
• Class 175 covers 4 to under 6 pounds per cubic foot: light, bulky freight.

Whether your product uses the scale at all depends on its NMFC item.

Freight class codes and NMFC item numbers

People often mix up two numbers on an LTL bill of lading. The freight class is the rating step, such as 70 or 125. The NMFC item number identifies the product description in the classification, and the item is what says which class applies: either one fixed class or the density scale, sometimes with sub-provisions for different densities or packaging. Both numbers belong on the BOL. A class without the right item behind it is a guess, and a guess is what inspections catch.

Reading an LTL freight class chart

A freight class chart you find online is usually a version of the density scale: a column of densities and a column of classes. Read it from your density, not from your product name. Three cautions apply. First, check the date, because the scale changed in 2025 and older charts are still everywhere. Second, the chart only applies to items that use the density scale; many products have their own class. Third, the chart gives an estimate. The carrier applies its tariff to the NMFC item, not to a chart on a website.

The ends of the scale

At the low end, class 50 is for the densest, sturdiest freight, such as heavy, compact items that stack and stow well. At the high end, the density scale stops at class 400 for freight under one pound per cubic foot, while some items carry classes up to 500 because of handling, stowability or liability on top of low density. If your freight is near either end, check its NMFC item before you rely on the density alone.

How to estimate your freight class

1. Measure each piece at its longest, widest and tallest points, including the pallet and anything that overhangs. Round up to the next inch.
2. Cube it: length × width × height in inches ÷ 1,728 = cubic feet, times the number of pieces.
3. Weigh it: the total weight, pallets and packaging included.
4. Divide: weight ÷ cubic feet = pounds per cubic foot.
5. Read the band from the scale.

The freight class and density calculator does all five steps for several pieces at once.

What is my freight class: a worked example

That's an EXAMPLE pallet. Note how close it sits to the next band: add about 35 pounds of product and the density passes 10, which on the scale moves it to class 92.5. Small changes in measurement or weight can move a shipment across a band, which is why carriers measure so carefully.

Who decides your class

You estimate; the NMFC and the carrier decide. Your product's NMFC item says whether it has a fixed class or follows the density scale. NMFTA's own tool for that, ClassIT+, finds the item number and confirms the class. Our guide to NMFC code lookup explains how lookup works and why free lists online can be wrong. The carrier then applies its tariff, and it can inspect your freight and correct the class.

Source: NMFTA, checked October 2026

The 2025 NMFC changes

NMFC Docket 2025-1 moved many items onto the density scale and changed the scale itself, effective in July 2025. If you shipped the same product before and after, its class may have changed even though nothing about the product did. Our guide to the NMFC freight class changes (coming soon) explains what changed, for whom, and how to check your items.

How freight class affects the price

Class doesn't set a price by itself; it chooses which rate in a carrier's tariff applies. Higher classes carry higher rates per hundredweight, so the same weight costs more at class 125 than at class 70. Weight breaks lower the rate as shipments get heavier, and most LTL prices are a negotiated discount off the base tariff, with a minimum charge and a fuel surcharge on top. The LTL freight cost estimator walks your carrier's numbers through that order and shows what a reclass one class up would cost.

Handling, stowability and liability in practice

Density is the characteristic you can measure, but the other three explain why two products of the same density can have different classes. Freight that needs special care to move, such as long, oddly shaped or unstable pieces, scores worse on handling. Freight that can't be stacked, has hazardous properties that limit what it rides with, or wastes space because of its shape scores worse on stowability. Fragile, perishable or high-value freight, or freight likely to damage other shipments, scores worse on liability. Those judgments are built into each NMFC item, which is why the item, not the scale alone, has the final word.

Reclasses and inspection fees

Carriers measure and weigh freight at terminals, often with dimensioning machines. If the actual density points to a different class than the BOL, the carrier reclasses the shipment, rebills it, and often adds an inspection or correction fee under its rules tariff. Each carrier publishes its own fees, so check the tariff of the carrier you use. The common causes are simple: leaving out the pallet, measuring the cartons instead of the overhang, rounding down, guessing the weight, or using the wrong NMFC item.

Packaging changes the class

Because density drives most classes, packaging matters. A pallet built tight to its footprint, without overhang, with cartons stacked square, has less cube than the same freight stacked loosely, and can land in a lower class. Our packaging and palletizing guidelines (coming soon) cover how to build a pallet that rides well and measures well. Carriers and shippers who manage cube closely often use freight cubing solutions to measure every shipment the same way.

Disputing a reclass

If a carrier reclasses your shipment and you think it's wrong, act quickly and in writing. Ask the carrier for the inspection record: the dimensions, the weight, any photos, and the NMFC item it applied. Compare them with your own measurements and photos from before pickup. Most disputes come down to one of three things: a dimension measured differently, a weight that wasn't what the BOL said, or a different NMFC item. If your records show the carrier's numbers are off, send them with a short request to correct the bill. If the carrier's numbers are right, fix the measurement habit that caused it, so the next shipment goes through clean.

Freight all kinds

Some shippers negotiate a single class for a mix of products, called freight all kinds, or FAK. It simplifies billing for mixed shipments and can lower the cost of high-class items, at the price of paying the agreed class on low-class items too. It's an agreement with a carrier, so it lives in the contract, not the NMFC.

Truckload and freight class

Freight class is an LTL tool. On a truckload, the shipper buys the space, so the rate usually comes per mile or per load, and class doesn't enter into it. Partial and volume loads sit in between, usually priced by linear feet or weight. For which truck suits which freight, see freight truck sizes.

What proves the class

If a carrier reclasses your freight and you disagree, your own measurements and photos are what you dispute with. Ask the carrier for its inspection record, compare the dimensions, and check the NMFC item it used.

Before you book: a freight class checklist for shippers

1. Look up the NMFC item for each product, and note whether it uses the density scale.
2. Measure every pallet with the pallet included, at the widest points, rounded up.
3. Weigh on a certified or calibrated scale; don't estimate.
4. Work out density and the band, and compare it with the item.
5. Put the item number, the class, the piece count and the weight on the BOL.
6. Photograph the pallet with a tape measure on each side before it leaves.

Six steps, a few minutes per shipment, and most reclasses never happen.

Freight class for carriers

Carriers who haul LTL-sized and partial freight in a 26 ft box or a van don't bill by class, but they meet it on every bill of lading. Density tells a carrier whether a load will fill the floor before the weight limit, or reach the weight limit with floor to spare. Light, bulky freight cubes out; dense freight weighs out. Knowing which kind a load is helps price it and plan what else can ride with it.

How our desk uses it

Our box truck dispatch desk checks the pallet count, the weight and the density of partial loads before an offer reaches you, so a 26 ft box gets freight that fits its floor and its payload. You approve every load. Send an application to see how it works on your lanes.