Three different capacity ceilings
Container planning usually has at least three limits: total internal volume, payload weight, and geometric fit. A carton can be under the theoretical CBM ceiling yet still waste space because its dimensions do not divide evenly into the container.
Orthogonal grid capacity
A basic calculator tests cartons aligned with the container axes. It is transparent and fast, but does not prove the best possible 3D packing pattern.
Real loading constraints
Door opening, floor strength, axle limits, weight distribution, dunnage, load securing, handling clearance, product fragility, and local regulations can all reduce practical capacity.
Use the calculator
Move from the explanation into a live calculation using the related PackFlow tool.