Freight Density Calculator

How the density calculator works

Density is the one number that ties together LTL pricing, trailer planning and packaging decisions: how much weight sits in each cubic foot of space you are buying. This calculator works it out the way the carrier will, one handling unit at a time.

• Enter what you know. If you have the dimensions of the finished pallet, enter those and leave the pallet set to "already included". If you only have the carton stack, enter the stack and pick the pallet it will ride on: the tool adds the deck height and the empty pallet weight.
• Footprint follows the bigger of load and pallet. A 46 × 38 inch stack on a 48 × 40 pallet is measured at 48 × 40. A stack wider than its pallet is measured at the stack, and the line is flagged as overhanging.
• Each line can have its own quantity. Three identical pallets go on one line with units set to 3. Different pallet builds go on separate lines.
• Results show every unit's measured size, cube and density, then the shipment total and its kg/m³ equivalent for anyone working in metric.

The density formula, imperial and metric

US carriers quote density in pcf. Most of the rest of the world thinks in kilograms per cubic metre, and some forwarders quote "kilos per CBM". They are the same quantity in different units, so a 10 pcf pallet is a 160 kg/m³ pallet.

Worked example: two Euro pallets into the US system

An importer has two pallets coming off an LCL container and moving on by LTL. Each is a 120 × 80 cm Euro pallet with a 110 cm stack of cartons weighing 240 kg, plus the 25 kg pallet.

• Finished unit: 120 × 80 × 124.4 cm (110 cm of freight on a 14.4 cm deck) and 265 kg.
• In inches that is 47.24 × 31.50 × 48.98. A US carrier rounding up bills it as 48 × 32 × 49 inches = 75,264 in³ = 43.56 ft³.
• 265 kg is 584.2 lb, so density is 584.2 ÷ 43.56 = 13.41 pcf, which earns class 85 on the density scale.
• Measured exactly, without rounding, the same pallet is 1.194 m³ and 221.9 kg/m³, or 13.85 pcf. The fractional inches cost a little under half a pound per cubic foot.

Neither figure is close to the 15 pcf break for class 70, so in this case the rounding does not change the class. On a pallet sitting at 15.2 pcf measured exactly, it would.

Density beyond freight class: cube-out or weigh-out

Density also tells you which limit you will hit first in a truck or container. A 53-foot dry van holds roughly 3,800 to 3,900 cubic feet and legally carries around 42,000 to 45,000 lb of cargo, depending on the tractor and trailer weight. Divide one by the other and the break-even is roughly 11 pcf. Freight lighter than that fills the trailer before it reaches the weight limit (it "cubes out"); denser freight hits the weight limit with floor space to spare. A 40-foot high cube container behaves the same way, with its break-even at roughly 350 to 400 kg/m³ depending on how much of the cube cartons really fill. Knowing which side of that line your freight sits on tells you whether to spend effort on better cube or on lighter packaging.

Mistakes that make density look better than it is

• Using spec-sheet carton sizes. Cartons bulge, and stretch wrap, corner boards and top caps add height. Measure a built pallet at least once.
• Forgetting the pallet. Five to six inches of deck height on a 48-inch stack is more than 10 % of the cube.
• Net weight instead of gross. Density uses the shipping weight: product, packaging, pallet and wrap.
• Assuming stacking helps. Double-stacking two pallets on the trailer does not change either pallet's density. Building one taller pallet instead of two short ones can, if it removes a deck.
• Confusing density with dimensional weight. Parcel carriers bill on a divisor, LTL carriers rate on density. The arithmetic is related but the thresholds are different; use the dimensional weight calculator for parcels.