Freight class calculator
Freight class is a number from 50 to 500 that LTL carriers use to price a shipment, and for many items it follows density: weight divided by cubic feet. Enter each handling unit’s length, width, height and weight. The calculator returns density in pounds per cubic foot and the class on NMFTA’s 13-sub density scale, the standard scale since July 19, 2025.
Updated October 12, 2026
Class estimate on NMFTA’s standard 13-sub density scale, in effect since July 19, 2025. The NMFC item for your product sets the class, and some items carry fixed classes for handling, stowability or liability. Confirm in NMFTA’s ClassIT+ or with your carrier.
How to calculate freight class
Measure each handling unit at its longest points, including the pallet, crate or packaging. NMFTA tells shippers to measure down to the inch and always include pallets or packaging.
Multiply length × width × height in inches, then divide by 1,728 to get cubic feet. In metric, divide cubic centimeters by 28,317.
Divide the weight in pounds by the cubic feet. The result is density in pounds per cubic foot (lb/ft³).
Find the density in the chart below. The class on that row is the estimate.
Check the NMFC item for your product. It tells you whether the product is classed by density at all, and whether a handling, stowability or liability provision sets a different class.
The formula in one line: density = weight in pounds ÷ (length × width × height in inches ÷ 1,728).
Freight class chart: the 2025 NMFC density scale
This is the standard 13-subprovision scale NMFTA published for density-based items. Each row covers a range of densities, and the lower bound is included in the row.
| Sub | Density (lb per cubic foot) | Class |
|---|---|---|
| 1 | Less than 1 | 400 |
| 2 | 1 but less than 2 | 300 |
| 3 | 2 but less than 4 | 250 |
| 4 | 4 but less than 6 | 175 |
| 5 | 6 but less than 8 | 125 |
| 6 | 8 but less than 10 | 100 |
| 7 | 10 but less than 12 | 92.5 |
| 8 | 12 but less than 15 | 85 |
| 9 | 15 but less than 22.5 | 70 |
| 10 | 22.5 but less than 30 | 65 |
| 11 | 30 but less than 35 | 60 |
| 12 | 35 but less than 50 | 55 |
| 13 | 50 or greater | 50 |
Source: NMFTA, Decoding Density, June 19, 2025. The NMFC has 18 classes from 50 to 500. The density scale uses 13 of them. Classes 77.5, 110, 150, 200 and 500 are still valid, but they are not on the standard scale; an item’s own provisions can assign them.
What changed on July 19, 2025
NMFTA’s Docket 2025-1 took effect on July 19, 2025. It extended the standard density scale from 11 subprovisions to 13 and amended NMFC items to use it. On that scale, dense freight can rate as low as class 55 (35 to under 50 lb/ft³) or class 50 (50 lb/ft³ or more). Check the date on any freight class chart you use: one published before July 19, 2025 predates the 13-row scale.
Worked examples
A 48 × 40 × 48 inch pallet at 500 pounds
48 × 40 × 48 = 92,160 cubic inches. 92,160 ÷ 1,728 = 53.33 cubic feet. 500 ÷ 53.33 = 9.38 lb/ft³. That falls in 8 but less than 10, so the estimate is class 100. At 533.3 pounds the same pallet would reach 10 lb/ft³ and class 92.5, which is the gap the calculator shows under the result.
The same carton stack, measured without its pallet
Cartons stacked 40 × 30 × 36 inches weigh 180 pounds: 25 cubic feet and 7.2 lb/ft³, which is class 125. On a 48 × 40 inch pallet that is 6 inches tall and weighs 40 pounds, the handling unit is really 48 × 40 × 42 inches and 220 pounds: 46.67 cubic feet and 4.71 lb/ft³, which is class 175. Leaving the pallet out understated the class: 125 instead of 175. Tick “My measurements do not include the pallet” in the calculator to add it.
Two crates in metric
Two crates of 120 × 100 × 150 cm at 350 kg each. Each crate is 1.8 cubic meters, or 63.57 cubic feet, and 771.6 pounds. Density is 12.14 lb/ft³ (194.4 kg/m³), which is class 85. Switch the calculator to cm and kg to enter these as they are.
Common mistakes that cause reclasses
NMFTA lists the errors it sees most often. When a carrier remeasures and finds a different density, the result can be a reclassification, a back charge or a delay.
Using default dimensions from old records instead of measuring the freight that is actually shipping.
Forgetting the pallet or packaging height.
Rounding measurements too generously.
Trusting a dimensioner that measures less accurately than the carrier’s.
Treating an irregular item like a box. Straight length × width × height can miss curves, contours and void fill.
Using a freight class chart from before July 19, 2025, when the scale had 11 rows instead of 13.
Assuming every product is classed by density. Many are, but an NMFC item can carry its own class.
Looking up an NMFC item number
NMFTA publishes the National Motor Freight Classification (NMFC) and licenses it through its ClassIT+ tool, so this page does not copy NMFC item text. Search ClassIT+ for your product, read whether the item is classed by density and whether any handling, stowability or liability note applies, then use this calculator for the density. If you are unsure, your carrier or a classification specialist can confirm the item.
Frequently asked questions
What is freight class?
Freight class is the rating an LTL carrier uses to price a shipment. The NMFC has 18 classes from 50 to 500, set by four transportation characteristics: density, handling, stowability and liability. Lower classes are dense, easy to handle and usually cost less per pound.
How do I calculate freight density?
Multiply length, width and height in inches, divide by 1,728 to get cubic feet, then divide the weight in pounds by the cubic feet. For a shipment of several units, add up all the weights and all the cubic feet first, then divide. The freight density calculator does this for up to ten units.
What freight class is 10 pounds per cubic foot?
On the 2025 scale, 10 lb/ft³ is the first density in the row “10 but less than 12”, so it is class 92.5 for a density-based item. Just below 10 lb/ft³ the class is 100.
Does the pallet count toward freight class?
Yes. NMFTA tells shippers to always include pallets or packaging when they measure. The pallet adds height and weight, and its footprint often sets the length and width of the handling unit.
What happens if I use the wrong freight class?
The carrier can reclassify the shipment and bill the difference. NMFTA notes that getting density wrong risks reclassifications, back charges and shipping delays.
Is the freight class the same as the NMFC code?
No. The NMFC item number identifies the commodity. The class is the rating that item carries, which can be a single class or a range that depends on density. NMFTA’s ClassIT+ gives both.
Who sets freight classes?
The National Motor Freight Traffic Association (NMFTA) publishes the NMFC. Its Freight Classification Development Council acts on changes to NMFC provisions through public dockets, such as Docket 2025-1.
Related calculators
Freight density calculator: density in lb/ft³ and kg/m³ for a whole shipment.
Pallet calculator: boxes per pallet, then the pallet’s class in one click.
Dimensional weight calculator: billable weight for UPS, FedEx and USPS parcels.
Sources
NMFTA, Decoding Density: The Freight Factor You Can’t Afford to Overlook, June 19, 2025
NMFTA, Disposition Bulletin 1371 for Docket 2025-1: supplement issued May 10, 2025, effective July 19, 2025
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