How the freight density calculator works
- Cubic feet = length × width × height (inches) ÷ 1,728 × pieces
- Density = total weight ÷ total cubic feet, in pounds per cubic foot (pcf)
- Class = the step on the density scale that density falls in
Measure to the outermost points: the pallet, any overhang, and the highest point of the load. Weigh with the pallet. Small measuring errors move density, and near a step boundary they can move the class.
The 2025 NMFC density scale
A 13-subprovision density scale, from class 400 under 1 pound per cubic foot to class 50 at 50 pounds per cubic foot or more. Each step covers a range of density:
| Density (pcf) | Class |
|---|---|
| under 1 | 400 |
| 1 to under 2 | 300 |
| 2 to under 4 | 250 |
| 4 to under 6 | 175 |
| 6 to under 8 | 125 |
| 8 to under 10 | 100 |
| 10 to under 12 | 92.5 |
| 12 to under 15 | 85 |
| 15 to under 22.5 | 70 |
| 22.5 to under 30 | 65 |
| 30 to under 35 | 60 |
| 35 to under 50 | 55 |
| 50 or more | 50 |
Source: NMFTA, NMFC Docket 2025-1 density scale (effective July 19, 2025), October 2026
A worked example
A shipper has 3 pallets, each 48 by 40 by 48 inches and 500 pounds with the pallet.
- Cubic feet
- 160
- Total weight
- 1,500 lb
- Density
- 9.38 pcf
- Estimated class
- 100
Stack the same freight 60 inches high at the same weight and density drops to 7.5 pcf, class 125. Freight that takes more room for its weight moves to a higher class, because it uses more trailer space per pound.
The same logic works the other way. Consolidate the load onto fewer, fuller pallets, or shrink-wrap it tighter so it takes less height, and density rises while the class number falls. Shippers who understand this pack to lower their class; carriers who understand it can tell at a glance whether a partial will take a little room or a lot. Run a few versions of the same shipment in the calculator to see how much the packing changes the result.
Measuring tips
- Measure the longest, widest and tallest points, including the pallet and any overhang.
- Round each dimension up to the next whole inch, the way most carriers will.
- Weigh the whole piece on a scale, pallet and wrap included, rather than adding up product weights.
- For mixed pieces of different sizes, run each size separately and add the weights and cubic feet.
- Near a step boundary, a single inch or a few pounds can change the class, so measure twice.
When the class on the paperwork is wrong
If a shipment is measured or weighed at a terminal and the density doesn't match the class on the bill of lading, it can be reclassed and rebilled. For a carrier hauling partials, a wrong class mostly matters when you're paid by class or weight, or when the space a partial takes doesn't match what was booked. Checking density before you accept a partial avoids both surprises.
Freight class lookup vs density
Not every commodity is classed by density. Many have their own item in the National Motor Freight Classification, which can set a class for reasons like fragility, handling or liability. When an item exists, it decides. This calculator is for freight classed by density and for checking whether a class on a bill of lading looks right.
Why carriers care about density
For a carrier running partials and LTL-size loads, density tells you what a shipment will do to your trailer. Light, bulky freight fills floor space long before it gets heavy; dense freight hits your weight limit with floor to spare. Use it with the pallet and linear feet calculator to see how much room a partial takes, and the rate per cwt calculator to compare what it pays.
We dispatch carriers, not shippers, so we don't quote LTL shipping. What we do is find full and partial loads for your truck, from 26 ft box trucks to 53 ft trailers, and send each one to you for a yes or no. Our fee is 5% for one truck with authority older than 6 months. See our LTL freight guide.