Cube Utilisation

Cube utilisation is the share of the available space a load actually occupies: cargo cube over available cube. It is one of the two numbers every load planner watches, and on its own it is almost meaningless — which is the point of teaching it beside weight utilisation rather than alone.

The first thing to get right is the ceiling you measure against. It is tempting to treat 100 per cent as the target, and it is not achievable. Pallet footprints do not tile a trailer floor: two 48 × 40 inch skids side by side across a 102 inch interior leave gaps, and turning them does not make the gaps go away. Product crush strength caps stack height, often well below the roof. Dunnage, airbags, load bars and the space a forklift needs to place the last skid all take their share. A realistic ceiling for palletised freight is 80 to 90 per cent of nominal, and a planner who scores 85 per cent has usually done as well as the geometry allows. Scoring the same load against a 100 per cent ideal makes a good result look like a failure, and worse, it makes people chase a number that does not exist.

The second thing is what a low figure actually tells you, which depends entirely on the other utilisation. If cube utilisation is low and weight utilisation is high, the load weighed out — the empty space is unavoidable and you are hauling dense freight in equipment sized for light. Nothing is wrong; the equipment is simply mismatched to the commodity, and if that happens routinely it is an equipment decision rather than a loading one. If both utilisations are low, the load was not built to fill anything, and that is a planning problem: a consolidation missed, an order released too early, a truck dispatched to hit a delivery window rather than to be full.

The third is measurement discipline. Cargo cube means the outside dimensions of everything on board, overhang and pallets included, for the same reason shipment density does — that is the space the trailer loses. Measuring the product instead of the loaded skid flatters the number by a few points and, worse, makes the plan disagree with the dock.

Used properly, cube utilisation is a diagnostic rather than a score. It tells you how much of what you paid for you used, and paired with its weight twin it tells you why.