Freight Class Examples: 8 Worked Calculations
Eight real-world shipments worked end to end - dimensions → cubic feet → density → freight class - covering every density bracket from class 50 to class 500. Every example uses the same formula: density = weight (lbs) ÷ (L × W × H in inches ÷ 1,728), and opens pre-filled in the freight class calculator.
Example 1: Small box of steel fittings → class 50
A single heavy carton of machined steel fittings. 150 lbs, 24 × 18 × 12 inches.
- Volume = (24 × 18 × 12) ÷ 1,728 = 5,184 ÷ 1,728 = 3.0 ft³
- Density = 150 ÷ 3.0 = 50.0 lbs/ft³
- 50.0 lbs/ft³ falls in the class 50 density bracket.
Dense metal goods sit at the very bottom of the scale - the cheapest freight to ship per pound. Open this example in the calculator →
Example 2: Half-height pallet of machine parts → class 55–60
A 48×40 pallet loaded 24" high with boxed machine parts. 900 lbs, 48 × 40 × 24 inches.
- Volume = (48 × 40 × 24) ÷ 1,728 = 46,080 ÷ 1,728 = 26.7 ft³
- Density = 900 ÷ 26.7 = 33.8 lbs/ft³
- 33.8 lbs/ft³ falls in the class 55–60 density bracket.
Keeping dense freight low and compact keeps the density high and the class low. Open this example in the calculator →
Example 3: Pallet of bottled beverages → class 65–70
A full-height 48×40 pallet of bottled drinks. 1,100 lbs, 48 × 40 × 48 inches.
- Volume = (48 × 40 × 48) ÷ 1,728 = 92,160 ÷ 1,728 = 53.3 ft³
- Density = 1,100 ÷ 53.3 = 20.6 lbs/ft³
- 20.6 lbs/ft³ falls in the class 65–70 density bracket.
Liquids in packaging are classic mid-density freight; NMFC 65–70 covers most bottled goods. Open this example in the calculator →
Example 4: Crated industrial machine → class 77.5–85
A wooden crate around a small industrial machine. 1,000 lbs, 60 × 48 × 48 inches.
- Volume = (60 × 48 × 48) ÷ 1,728 = 138,240 ÷ 1,728 = 80.0 ft³
- Density = 1,000 ÷ 80.0 = 12.5 lbs/ft³
- 12.5 lbs/ft³ falls in the class 77.5–85 density bracket.
The crate adds volume without much weight, pushing the density below the bare machine’s. Open this example in the calculator →
Example 5: Standard pallet of boxed goods → class 92.5–110
The classic LTL shipment: a 48×40×48 pallet of mixed cartons. 500 lbs, 48 × 40 × 48 inches.
- Volume = (48 × 40 × 48) ÷ 1,728 = 92,160 ÷ 1,728 = 53.3 ft³
- Density = 500 ÷ 53.3 = 9.4 lbs/ft³
- 9.4 lbs/ft³ falls in the class 92.5–110 density bracket.
At ~500 lbs, the typical mixed pallet lands right around class 100 - the most common estimate you’ll see quoted. Open this example in the calculator →
Example 6: Upholstered couch → class 125–175
An 84" fabric sofa, blanket-wrapped on a skid. 400 lbs, 84 × 40 × 36 inches.
- Volume = (84 × 40 × 36) ÷ 1,728 = 120,960 ÷ 1,728 = 70.0 ft³
- Density = 400 ÷ 70.0 = 5.7 lbs/ft³
- 5.7 lbs/ft³ falls in the class 125–175 density bracket.
Furniture is light for its footprint; the NMFC rates stuffed furniture around class 175. Open this example in the calculator →
Example 7: Queen mattress → class 200–300
A boxed queen mattress shipped flat. 100 lbs, 80 × 60 × 14 inches.
- Volume = (80 × 60 × 14) ÷ 1,728 = 67,200 ÷ 1,728 = 38.9 ft³
- Density = 100 ÷ 38.9 = 2.6 lbs/ft³
- 2.6 lbs/ft³ falls in the class 200–300 density bracket.
Matches the official listing: NMFC 79550 (mattresses, box springs) is rated class 250–300. Open this example in the calculator →
Example 8: Plastic kayak → class 400–500
A 12-foot rotomolded kayak, foam-wrapped. 90 lbs, 144 × 30 × 24 inches.
- Volume = (144 × 30 × 24) ÷ 1,728 = 103,680 ÷ 1,728 = 60.0 ft³
- Density = 90 ÷ 60.0 = 1.5 lbs/ft³
- 1.5 lbs/ft³ falls in the class 400–500 density bracket.
Huge volume, almost no weight - the most expensive bracket per pound of anything in LTL. Open this example in the calculator →
Bonus: multiple pallets in one shipment → class 77.5–85
Two 48 × 40 × 48 pallets shipping together: one weighs 800 lbs, the other 500 lbs. Use the totals, not the average of two classes:
- Total volume = 2 × 53.3 = 106.7 ft³
- Total weight = 800 + 500 = 1,300 lbs
- Density = 1,300 ÷ 106.7 = 12.2 lbs/ft³ → class 77.5–85
Averaging the two pallets’ individual classes would give the wrong answer - density is a ratio of totals.
Remember: density is the estimate, the NMFC listing is the answer
These examples use the standard density-to-class rule of thumb (see the full chart). Many commodities carry a fixed NMFC class or their own density sub-brackets - look up the commodity for the official rating, or classify programmatically with the NMFC API.
Frequently asked questions
What freight class is a standard 48x40 pallet?
It depends on the loaded weight and height. A 48×40×48-inch pallet weighing about 500 lbs has a density of roughly 9.4 lbs/ft³, which lands around class 92.5–110. The same pallet loaded to 1,100 lbs is about 20.6 lbs/ft³ - class 65–70. Weigh and measure the shipment as it will actually ship, then compute density.
How do I calculate freight class for multiple pallets?
Add up the total weight of all pieces and divide by the total volume in cubic feet. For example, two 48×40×48 pallets (53.3 ft³ each, 106.7 ft³ total) weighing 1,300 lbs together have a density of about 12.2 lbs/ft³ - class 77.5–85. Do not average the per-pallet classes.
Do I measure the freight or the pallet?
Measure the shipment as it ships: length, width, and height including the pallet, packaging, and any overhang, and include the pallet’s own weight (typically 35–50 lbs for a wooden 48×40). Carriers dimension the whole handling unit, so calculating from bare-product dimensions understates volume and overstates density.
What if my density lands on the edge of a bracket?
The generic density-to-class chart is a rule of thumb. Many NMFC listings define their own density sub-brackets with exact cutoffs, and some commodities have a fixed class regardless of density. When you are near a boundary, look up the commodity’s NMFC listing for the official break points.