Free tool

Freight density calculator

Enter the dimensions, weight, and piece count of your freight to get its density in pounds per cubic foot.

Shipment

Dimensions of one piece in inches, including the pallet. Weight is the total for all pieces.

Density

Enter the dimensions and weight to see pounds per cubic foot.

Density to freight class

The lower bound of each band is inclusive: exactly 22.5 lb/ft³ rates as class 65, not 70.

NMFC density scale: freight class by pounds per cubic foot, densest first.
ClassFrom (lb/ft³)Up to (lb/ft³)
5050No limit
5535Under 50
6030Under 35
6522.5Under 30
7015Under 22.5
77.513.5Under 15
8512Under 13.5
92.510.5Under 12
1009Under 10.5
1108Under 9
1257Under 8
1506Under 7
1755Under 6
2004Under 5
2503Under 4
3002Under 3
4001Under 2
5000Under 1

Need the class as well? Use the freight class calculator.

About freight density

What freight density is

Density is weight divided by volume: pounds of freight per cubic foot of the space it takes up. A 48 × 40 × 48 inch pallet occupies 53.33 cubic feet; at 500 pounds its density is 9.38 lb/ft³. Carriers care because a trailer fills up by space long before it reaches its weight limit, so light, bulky freight costs more to move per pound than dense freight.

The formula

Cubic feet = length × width × height in inches ÷ 1,728. Density = total weight in pounds ÷ cubic feet. For several identical pieces, multiply one piece's cube by the count and divide the total weight by that. Keep the exact measurements until the end — carriers do, and the class breakpoints (10.5, 15, 22.5 lb/ft³ and so on) are hard lines.

Why it changes your rate

Density is the first of the four NMFC classification factors, and for most general freight it is the one that decides the class, which in turn sets the rate. Small changes matter: the same 500-pound pallet moves from class 100 to class 92.5 if it is packed six inches shorter, because 48 × 40 × 42 inches puts its density over 10.5 lb/ft³.

Density and dimensional weight

Parcel carriers apply the same idea differently: they bill the greater of actual weight and dimensional weight, which is cube divided by a fixed divisor. LTL carriers use density to place freight in a class instead, and a growing number also offer density-based rates that skip class altogether. Either way, an accurate measurement is what keeps the invoice matching the quote.

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Freight density calculator — Flutter Freight