WORKBENCH / REFERENCE

Methods, with the assumptions visible.

Sources checked 2 October 2026.

Volume and units

Carton volume uses outside dimensions. Input supports up to three decimal places. Dimensions and weights use fixed-scale integers internally so a rounding artefact does not create a false fit. One inch is 2.54 cm; one pound is 0.45359237 kg. Unit switches calculate from the displayed measurements, rounded to three decimals. This can change a tight fit or a billing boundary; review converted inputs. Switching back restores each unchanged measurement to its original value. Edited measurements are converted from the new entry.

Dimensional weight

Select centimetres/kilograms or inches/pounds, then set your divisor and rounding. Our 5,000 and 139 examples use public DHL formula guidance. The default one-unit billing step and imperial upward dimension rounding are editable planning assumptions, not a worldwide carrier policy. The UK DHL half-kilogram example shows why service rules differ. Each carton is rounded before quantity is applied.

Load layout

We compare uniform grids and two-section layer layouts for identical rectangular cartons. A chosen layer repeats at the same carton height. The smaller of geometric capacity and payload capacity limits the count. Payload is maximum gross weight less empty equipment weight. The layout may use a partial final layer. We do not model mixed cargo, weight distribution, box compression, restraint, interlocking, loading sequence or global optimisation.

When door limits are supplied, the full loading envelope uses the smaller interior/door width and height. This is deliberately conservative; loading individual boxes through a door can sometimes use more interior space. The diagram shows at most 400 cartons in the first loaded layer; this cap does not change calculated capacity.

Equipment examples

The EPAL example uses a 120 × 80 cm floor, a 14.4 cm base, about 25 kg tare and 1,500 kg working load. Its 160 cm total-height limit is our editable example. The 20 ft container example uses one published Hapag-Lloyd specification. Real equipment dimensions, tare and payload vary.

Primary sources

Input limits

Up to 100 carton rows, 1,000,000 cartons per row and three decimal places. The layer planner supports up to 2,000 possible carton positions along an edge. Measurements, capacity and carrier acceptance must be checked against the actual shipment.