In the United States, less-than-truckload (LTL) freight is priced by class under the National Motor Freight Classification (NMFC), maintained by the NMFTA. Classes run from 50 for dense, robust freight to 400 for light, bulky freight; the higher the class, the higher the rate per hundred pounds. Since Docket 2025-1 took effect on 19 July 2025, most commodities without special handling, stowability or liability concerns are classed by density alone on a 13-tier scale, from class 400 (under 1 lb/ft³) to class 50 (50 lb/ft³ or more).
Measure the shipment as it will travel – including the pallet and any overhang, at its longest, widest and tallest points – and weigh it with the pallet. Enter the dimensions of one piece, its weight and the number of identical pieces. The calculator gives the cubic feet, the density and the class, and how much weight you would have to add (or volume save) to drop into the next, cheaper class.
About 200 NMFC items keep a commodity-specific class, and carriers can re-class a shipment if the density is misstated, so check the item number for your goods. The older 18-class density guideline is offered for comparison with past quotes.
How to use the Freight Class Calculator
- Length
- Width
- Height
- Weight per piece (incl. pallet)
- Number of pieces (pallets)
- Density scale
- Freight rate per 100 lb (optional)
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Total volume in cubic feet is the product of the dimensions in inches ÷ 1,728, times the number of pieces; density is total pounds ÷ total cubic feet. The class is read from the chosen density table, and the cost multiplies hundredweights by your rate.
Worked example
One pallet of 48 × 40 × 48 in weighing 500 lb: 92,160 in³ ÷ 1,728 = 53.33 ft³, density 500 ÷ 53.33 = 9.38 lb/ft³ – class 100 on the 13-tier scale (8 to under 10 lb/ft³), class 125 on the legacy guideline. Reaching 10 lb/ft³ (class 92.5) would need 0.63 × 53.33 ≈ 33 lb more. A 260 lb shipment occupying 60 ft³ has a density of 4.33 lb/ft³ – class 175 on the new scale.
NMFC density scale (from 19 July 2025)
| Density (lb/ft³) | Class |
|---|---|
| Less than 1 | 400 |
| 1 – < 2 | 300 |
| 2 – < 4 | 250 |
| 4 – < 6 | 175 |
| 6 – < 8 | 125 |
| 8 – < 10 | 100 |
| 10 – < 12 | 92.5 |
| 12 – < 15 | 85 |
| 15 – < 22.5 | 70 |
| 22.5 – < 30 | 65 |
| 30 – < 35 | 60 |
| 35 – < 50 | 55 |
| 50 or more | 50 |
Tips
- Measure the longest points of the package, including bulges.
- Check your carrier’s current divisor and rounding rules.
- Every field has a unit menu – cm, inches, kg and lb all work.
- Everything is calculated in your browser.
Common mistakes to avoid
- Using the wrong dimensional divisor for the carrier or service.
- Forgetting pallet height and overhang limits.
- Rounding dimensions down instead of up.
Inputs explained
| Field | What to enter |
|---|---|
| Length | Units: in, cm, ft, m |
| Width | Units: in, cm, ft, m |
| Height | Units: in, cm, ft, m |
| Weight per piece (incl. pallet) | Units: lb, kg, t |
| Number of pieces (pallets) | A number |
| Density scale | Choose one: NMFC 13-tier scale (from 19 July 2025), Legacy density guideline (before July 2025) |
| Freight rate per 100 lb (optional) | Amount in $ |
What each result means
- Total volume = [Length]×[Width]×[Height]×[Number of pieces (pallets)]÷0.028316846592
- Total weight = [Weight per piece (incl. pallet)]×[Number of pieces (pallets)]÷0.45359237
- Density = [Total weight]÷[Total volume]
- Estimated linehaul cost = [Total weight]÷100×[Freight rate per 100 lb (optional)]
Formula
Density (lb/ft³) = total weight (lb) ÷ total volume (ft³) · volume (ft³) = L × W × H (in) ÷ 1,728 · class from the density table · cost ≈ weight ÷ 100 × rate per cwt
Worked example
Inputs — Length: 48 in; Width: 40 in; Height: 48 in; Weight per piece (incl. pallet): 500 lb; Number of pieces (pallets): 1; Density scale: NMFC 13-tier scale (from 19 July 2025); Freight rate per 100 lb (optional): $0.
Results — Total volume = 53.33 ft³; Total weight = 500 lb; Density = 9.38 lb/ft³; Freight class = 100; Density needed for the next lower class = 10 lb/ft³; Weight to add to reach it = 33 lb; Estimated linehaul cost = $0.00.
Key terms
- NMFC
- National Motor Freight Classification, the US LTL class system.
- Density
- Pounds per cubic foot of the shipment.
- LTL
- Less-than-truckload freight.
- CWT
- Hundredweight – 100 lb, the unit of LTL rates.
Frequently asked questions
How do I calculate freight class?
Find the density: weight in pounds ÷ volume in cubic feet. A 48 × 40 × 48 in pallet is 53.33 ft³; at 500 lb that is 9.38 lb/ft³ – class 100.
What changed in July 2025?
NMFTA Docket 2025-1 moved most items to a 13-tier density scale (classes 50 to 400) and removed many commodity-specific listings.
What density is class 50?
50 lb/ft³ or more on the new scale.
What is the highest freight class?
Class 400, for freight under 1 lb/ft³ on the new scale (500 on the old one).
Should I include the pallet?
Yes – weigh and measure the shipment as tendered, pallet included.
How can I lower my freight class?
Make the load denser: use smaller pallets, stack tighter, avoid overhang, or combine with heavier goods.
Does every item use density?
No – roughly 200 items with handling, stowability or liability concerns keep a fixed class; check the NMFC item number.