What freight class actually is
The National Motor Freight Classification is a standard way of describing freight so a carrier and a shipper mean the same thing by the same words. It sorts everything into eighteen classes, from 50 at the dense end to 500 at the light and awkward end. Lower classes cost less to ship.
Four things decide where freight lands: its density, how easily it stows alongside other freight, how much handling it needs, and how much liability it carries for the carrier. For most general commodities the first of those does the work, and the other three only come into it when something about the freight is unusual.
The calculation, in three steps
1. Work out the volume in cubic feet. Multiply length by width by height in inches, then divide by 1,728. Measure the whole handling unit, not the product — that means the pallet, the packaging and any overhang.
2. Divide the weight by the volume. That gives density in pounds per cubic foot. Use the shipping weight, pallet included.
3. Read the class off the scale. Density maps to a class through the thirteen subprovisions below.
The density scale
Thirteen subprovisions, current as of Docket 2025-1. Each class links to what it means and what tends to land there.
| Sub | Density (PCF) | Class |
|---|---|---|
| 13 | 50 or greater | 50 |
| 12 | 35 to less than 50 | 55 |
| 11 | 30 to less than 35 | 60 |
| 10 | 22.5 to less than 30 | 65 |
| 9 | 15 to less than 22.5 | 70 |
| 8 | 12 to less than 15 | 85 |
| 7 | 10 to less than 12 | 92.5 |
| 6 | 8 to less than 10 | 100 |
| 5 | 6 to less than 8 | 125 |
| 4 | 4 to less than 6 | 175 |
| 3 | 2 to less than 4 | 250 |
| 2 | 1 to less than 2 | 300 |
| 1 | Less than 1 | 400 |
Five classes are missing from that table on purpose. 77.5, 110, 150, 200 and 500 are not produced by this scale — they are named by particular NMFC items instead. All eighteen classes.
Not everything uses the thirteen subprovisions
Plenty of commodities do not classify this way at all, and the scale above will give you a confident wrong answer for those.
Some items carry one straight class no matter what they weigh per cubic foot. Some have their own set of breaks — three, say, rather than thirteen — so the density still matters but the boundaries are different. And some are classified on length as well as density, which no density calculator can work out on its own.
The item number is what tells you which of those applies. Work out your density by all means, but if you have not confirmed that your commodity is one of the density-based ones, you have calculated a number rather than found your class.
Where the NMFC item number comes in
Density gives you a class. The NMFC item number is what tells a carrier which rule to apply in the first place — whether your commodity is classified by density at all, or carries a fixed class regardless of what it weighs.
That is why two pallets that look identical on a dock can bill differently. The item number depends on what the freight is made of, how it is packaged, and sometimes its density. The same product crated and shrink-wrapped can carry different numbers.
There is no free public lookup for it. The classification is published by the NMFTA and searching it properly needs a paid subscription. How to find your NMFC item number.
What changed in July 2025
Docket 2025-1 consolidated a large number of listings and moved much of that freight onto the density scale above. A commodity that used to carry one fixed class may now classify differently depending on how it is packed.
Most freight class charts published online predate that change. If you are working from a table that lists commodities against fixed classes, check when it was written. What changed in Docket 2025-1.
Getting it wrong costs money after the fact
Carriers inspect a portion of what they haul. If they measure your freight and find a different class, they reclassify it and bill the difference — usually weeks after delivery, and long after you quoted the job to your own customer.
That correction is hard to dispute, because the carrier had the freight in front of them and you did not. Measuring accurately before it moves is the only reliable defense. Exact weights and real dimensions, not rounded estimates: a pallet declared at 500 lb reads like a guess, and one declared at 527 lb reads like something that was weighed.
Work out your class in about a minute.
Enter dimensions and weight and the calculator gives you density and the class it lands in, on the current scale. If you would rather have the item numbers checked, send us up to 10 and we will do it at no charge.