Freight Class Calculator

One line per pallet — density in pounds per cubic foot and the NMFTA class the carrier will rate it at.

UnitsLength (in)Width (in)Height (in)Weight each (lb)lb/ft³
8.41
8.67

Freight class

Class 110

Density
8.53 lb/ft³
Total weight
900 lb
Total volume
105.56 ft³
Handling units
2 on 2 lines
Pallet height included
5.5″ per unit

Density sets the class for most commodities, but the binding answer is the NMFC item number for what you are actually shipping. Confirm with your carrier before the bill of lading goes out.

Shipping lumber? Work out what the load weighs first →

How this is calculated

height    = stack height(in) + pallet height(in)
unit ft³  = length(in) × width(in) × height(in) / 1728
shipment  = Σ (unit ft³ × units)
density   = total weight(lb) / total ft³
class     = the NMFTA band the density falls in

The division by 1,728 is only cubic inches to cubic feet — twelve cubed. Everything else is one division, which is why freight class feels harder than it is: the arithmetic is trivial and the measuring is where shipments go wrong. Carriers dimension the loaded pallet at its widest and tallest point, so overhanging cartons, shrink wrap and cornerboard all count, and none of them add weight to offset the volume they add.

Density is computed across the whole shipment rather than pallet by pallet, because the carrier rates one class against the bill of lading. A 200 lb pallet moving alongside a 1,400 lb pallet of the same size averages to 15 lb/ft³ and the pair bills at class 70 — neither the 2.5 nor the 17.5 they would reach on their own.

Density to freight class

Density (lb/ft³)ClassTypical freight
50.0 and over50Bricks, nails, dense loose freight on a pallet
35.0 to under 50.055Hardwood flooring, tile, cement
30.0 to under 35.060Car parts, steel cable
22.5 to under 30.065Bottled drinks, books, boxed hardware
15.0 to under 22.570Engines, food in cases
13.5 to under 15.077.5Tires, bathroom fixtures
12.0 to under 13.585Crated machinery, transmissions
10.5 to under 12.092.5Appliances, computers, boxed goods
9.0 to under 10.5100Boat covers, canvas, wine cases
8.0 to under 9.0110Cabinets, framed art
7.0 to under 8.0125Small household appliances
6.0 to under 7.0150Auto sheet metal, bookcases
5.0 to under 6.0175Clothing, couches, stuffed furniture
4.0 to under 5.0200Sheet metal parts, aircraft parts
3.0 to under 4.0250Mattresses, televisions, bamboo furniture
2.0 to under 3.0300Wood cabinets, tables, chairs
1.0 to under 2.0400Antlers, light bulky goods
Under 1.0500Ping pong balls, bags of gold dust

Every row here is generated from the same table the calculator runs, so the published bands cannot drift from the tool. The bounds are inclusive at the bottom: a shipment at exactly 15.0 lb/ft³ is class 70, not 77.5. That matters more than it sounds, because shipments cluster on round numbers and a tenth of a pound either way moves the rate. The commodity examples are orientation only — they are not a substitute for the NMFC item.

A standard 48 × 40 pallet at common heights

Stack heightVolumeAt 400 lbAt 800 lbAt 1,500 lb
24″32.8 ft³Class 85Class 65Class 55
36″46.1 ft³Class 110Class 70Class 60
48″59.4 ft³Class 150Class 85Class 65
60″72.8 ft³Class 175Class 92.5Class 70
72″86.1 ft³Class 200Class 100Class 70

Read this down a column rather than across: at a fixed weight, every foot of extra height pushes the class up a band or two. That is the practical lesson of density pricing — the cheapest thing you can do to a shipment is usually to make it shorter, not lighter. All figures include the 5.5-inch pallet.

Frequently asked questions

How do I calculate freight class?

Multiply length by width by height in inches to get cubic inches, divide by 1,728 for cubic feet, then divide the shipment weight by that volume. The result is density in pounds per cubic foot, and the NMFTA scale turns density into one of eighteen classes from 50 to 500. Denser freight gets a lower class and a lower rate, because a carrier fills a trailer by volume long before it hits the weight limit.

Do the pallet dimensions and weight count?

Yes, both. The carrier measures and weighs what it picks up, so a 40-inch stack on a standard wooden pallet is a 45.5-inch handling unit, and the 35 to 50 pounds of the pallet itself is part of the shipment weight. Calculating on the carton stack alone comes out denser than the carrier will measure, and that is the most common reason a class gets corrected on the invoice.

Does each pallet get its own class?

Not normally. A carrier rates the shipment as a whole, so density is computed on the total weight over the total volume, and one class applies to everything on the bill of lading. That is why a light pallet moving with a heavy one lands somewhere in the middle rather than being billed separately, and it is also why splitting a shipment across two bills sometimes changes what you pay.

Is density the only thing that sets the class?

No. Density is the main input and for many commodities it is decisive, but the classification system also weighs stowability, ease of handling and liability. Something awkwardly shaped, hazardous, fragile or unusually valuable can be classed above what its density alone would suggest. The authoritative answer for a given commodity is its NMFC item number, not a density calculation.

Why did the carrier change my class after pickup?

Carriers run dimensioners and scales at the terminal, and a shipment that measures differently from the bill of lading gets corrected, usually with a fee on top of the rate difference. The usual culprits are pallet height, cartons overhanging the pallet edge, and shrink wrap or cornerboard adding an inch. Measure the loaded pallet at its widest and tallest point, not the carton stack you built.

What density should I aim for?

Anything at or above 15 lb/ft³ lands at class 70 or better, which is a sensible target for palletized goods. Below about 8 lb/ft³ the class climbs fast and each unused inch of height costs real money — restacking to a shorter, fuller pallet often saves more than negotiating the rate. Under 1 lb/ft³ you are at class 500, where the freight is priced as though the trailer space itself were the product.

Results are planning estimates. Density decides the class for many commodities, but stowability, handling and liability also feed the classification, and the binding figure is the NMFC item number for your commodity. Carriers reweigh and re-dimension at the terminal; confirm the class with yours before shipping.

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