Density is one division: gross pounds over cubic feet. Almost nobody gets the arithmetic wrong. What goes wrong is the measuring, and a load measured at the wrong moment produces a class the terminal quietly corrects on the invoice three weeks later.
The carrier bills the space the finished load occupies, wrap, overhang and pallet included.
Multiply length by width by height in inches and divide by 1,728. FedEx Freight publishes that sequence on its class calculator page, read 2026-07-28, and then divides weight by the result. Estes puts the second half in a single line on its density page, read the same day: dividing the weight of the shipment by the number of cubic feet will provide the density.
The figure a carrier bills against is the space the load occupies in a trailer, so the tape goes around the finished unit: deck included, wrap included, and the greatest overhang on each side. A carton measured on the workbench is not the shipment the driver collects.
The pricing guide Old Dominion publishes, read 2026-07-28, counts the weight of the item, the packaging and the pallet. A wooden deck is real pounds and real height, and on a light load it can shift the density a full band in either direction.
These are five shipments we measured and put through our own parcel calculator on 2026-07-28, all on the same lane from Berkeley Heights, NJ 07922 to Dallas, TX 75201. The density column is plain division. The last column is the cheapest ground price that came back, or the fact that nothing came back at all.
| Load | Cubic feet | Density | Band class | Cheapest parcel price |
|---|---|---|---|---|
| 12 x 12 x 12 in, 60 lb | 1.00 | 60.00 lb per cu ft | 50 | $85.45 |
| 24 x 18 x 14 in, 40 lb | 3.50 | 11.43 lb per cu ft | 92.5 | $48.08 |
| 36 x 30 x 30 in, 25 lb | 18.75 | 1.33 lb per cu ft | 300 | $263.20 |
| 60 x 30 x 30 in, 90 lb | 31.25 | 2.88 lb per cu ft | 250 | no rates returned |
| 48 x 40 x 48 in, 500 lb | 53.33 | 9.38 lb per cu ft | 100 | no rates returned |
Rows one and three carry the whole lesson. The 60 lb box is dense enough for the bottom rung of the ladder and the 25 lb box sits near the top, and on our own lane the light one cost more than three times the heavy one to move as a parcel. Weight is not the expensive thing. Space is. The last two rows are shipments our parcel calculator declined outright, which is the boundary where a person has to price the move.
The accessorial reference Old Dominion publishes from tariff ODFL 100-Q, effective January 7, 2026, carries a minimum charge for low density freight. It reaches shipments below 3 pounds per cubic foot that need between 350 and 749 cubic feet, and shipments below 6 pounds per cubic foot that need 750 cubic feet or more. Past those points the trailer space is the product being sold.
Estes states on its density page, read 2026-07-28, that it may reweigh and dimension freight to confirm density once the shipment has been collected. A remeasure that moves you a band is not a dispute. It is the tariff working exactly as filed.
A parcel carrier converts volume into a billable weight and charges the greater of that and the scale weight. An LTL carrier converts the same volume into a class. Same instinct, different arithmetic, and a light bulky carton comes off badly in both systems at once.
Once you have a density you have an opening class, and once you have a class you can ask a carrier something specific. Below about 150 lb and inside the parcel size limits, our calculator will price the box directly. Above that, the numbers on this page are what a person needs from you before quoting.
Convert density to a class Compare the parcel side Send the measurements to a person
Multiply length by width by height in inches, divide by 1,728 for cubic feet, then divide the gross weight in pounds by that figure. The answer is in pounds per cubic foot, which is what a carrier means by density.
Yes. Old Dominion counts the item, the packaging and the pallet in the weight, and the dimensions are taken around the wrapped load, so the deck adds both height and pounds to the figure.
Old Dominion publishes a minimum charge for low density freight reaching shipments under 3 pounds per cubic foot that need 350 to 749 cubic feet, and shipments under 6 pounds per cubic foot that need 750 cubic feet or more.
No. A parcel carrier turns volume into a billable weight and charges the greater of that and the scale weight, while an LTL carrier turns the same volume into a class. Both penalise a light bulky box, by different routes.