Worked example
One pallet measuring 48 × 40 × 50 inches, weighing 600 pounds with the pallet and shrink wrap included.
- Volume: 48 × 40 × 50 = 96,000 cubic inches. Divide by 1,728 and you get 55.56 cubic feet.
- Density: 600 ÷ 55.56 = 10.80 pounds per cubic foot.
- That lands in the 10 to under 12 band, which is class 92.5.
Note how close that is to the edge. Shave four inches off the height and the same 600 pounds becomes 11.75 lb/ft³, still class 92.5. Take off ten inches and it reaches 12.96 lb/ft³, which drops it to class 85 and a cheaper rate.
The formula
Cubic feet = L × W × H (inches) ÷ 1,728 Density = weight (lb) ÷ cubic feet Class = the NMFC band that density falls in
Density bands are lower-inclusive and upper-exclusive. A shipment at exactly 10.00 lb/ft³ is class 92.5, not class 100, and one at exactly 22.50 is class 65. Those boundaries are where most classification disputes start.
What changed in 2025
On July 19, 2025 the NMFTA finished the largest restructuring of the NMFC in decades. Most commodities that previously carried a fixed class moved onto a single 13-tier density scale, and many sub-provisions were retired entirely.
The practical effect is that how you pack now decides what you pay. Two shipments of the same product, one loosely stacked and one packed tight, can land three classes apart. If you have not reviewed your NMFC listings since the change, your rate sheet is probably describing freight you no longer ship.
Reading the scale, and why the edges matter
The density bands are lower-inclusive and upper-exclusive, which sounds like pedantry until a shipment lands on a boundary. A density of exactly 10.00 pounds per cubic foot is class 92.5, not class 100. Exactly 22.50 is class 65, not class 70.
The bands are also uneven, and that is where the money is. From 15 to 22.5 lb/ft³ is a single band, so a shipment can get half again as dense without changing class at all. But between 8 and 12 there are two bands in four pounds, so a small packing change moves you twice.
The practical rule: before you invest in tighter packaging, check where your current density sits relative to the next band down. If you are at 10.8 and the next break is at 12, you need a 12% improvement and it is probably reachable. If you are at 15.5 and the next break is 22.5, you need 45% and it almost certainly is not.
Common mistakes
- Leaving the pallet out. Class is calculated on the handling unit as it sits on the dock. The pallet adds height and weight, and the carrier will measure both.
- Measuring the box instead of the freight. If cartons overhang the pallet, the overhang is the real dimension. Carriers measure the greatest length and width, not the pallet footprint.
- Using the nominal pallet height. A 48 inch tall stack on a 5.5 inch deck is 53.5 inches, not 48.
- Rating a mixed shipment as one piece. If pallets differ, work out the combined density across all of them rather than classing the largest one and hoping.
- Rounding density before reading the class. Round for display, not for the lookup. A density of 11.996 is class 92.5 even though it prints as 12.00.
FAQ
What is freight class?
A code from 50 to 400 that LTL carriers use to price a shipment. Since July 2025 most commodities are classed on density alone, so a denser shipment gets a lower class and a cheaper rate.
How do I calculate freight class?
Divide the shipment weight by its volume in cubic feet to get density in pounds per cubic foot, then read the class off the NMFC density scale. Measure the outside of the pallet, including overhang.
Do I include the pallet in the measurements?
Yes. Measure the greatest length, width and height of the handling unit as it sits on the dock, pallet included, and weigh it with the pallet and all packaging.
What changed in the 2025 NMFC update?
The NMFTA moved most commodities to a single 13-tier density scale and retired many fixed class listings. Items that used to carry a fixed class now depend on how densely you pack them.
What happens if I declare the wrong class?
The carrier reweighs and remeasures, then reclasses the shipment and issues a balance-due invoice, often with an inspection fee. Getting the density right up front is cheaper than disputing it later.
Rules last checked: Sep 24, 2026
Estimate only. Confirm with your carrier before booking.