How the container carton-fit estimate works
ShipMeasure tests the six basic rectangular orientations of a carton against example internal dimensions for a 20-foot standard, 40-foot standard or 40-foot high-cube dry container. It counts only whole cartons along each axis. If you enter carton weight, the calculator also compares the geometric fit with the example container payload and reports the lower planning capacity.
This is deliberately more conservative than dividing container cubic capacity by carton CBM. A volume-only calculation assumes every cubic centimetre can be filled, but real rectangular cartons often leave unusable space because their dimensions do not divide evenly into the container dimensions.
Why “container CBM ÷ carton CBM” is not enough
A 20-foot dry container may be described as roughly 33.2 m³ in example equipment specifications. If a carton is 0.096 m³, simple division suggests about 345 cartons. That number is only a volume ratio. A whole-carton layout can produce a different result because cartons have to fit along the actual length, width and height—and still pass through the door and be physically loaded.
Volume and payload are separate constraints
Bulky light cargo normally runs out of space first. Dense products can reach the container payload before using all available cubic capacity. The connected Shipment Workspace compares the total shipment's CBM and gross cargo weight across the three dry-container profiles, helping expose whether volume or payload is the headline constraint.
Why actual equipment can differ
ShipMeasure uses current Hapag-Lloyd dry-container specifications as transparent planning references. Hapag-Lloyd itself notes that container specifications vary by manufacturer. A container supplied on the day can therefore differ slightly in internal dimensions, tare and payload. Door opening dimensions are also smaller than some internal dimensions and can prevent an otherwise mathematical fit.
Other reasons a real load plan may be lower
- pallets, skids, dunnage and bracing consume space;
- cartons may be non-stackable or restricted to one orientation;
- axle, road or verified-gross-mass limits can be more restrictive than equipment payload;
- weight distribution and centre of gravity matter, not just total kilograms;
- dangerous goods, ventilation, moisture control or segregation may change how cargo is loaded.
Use this calculator for early feasibility and quote comparison, then confirm critical loads with the carrier, forwarder or warehouse responsible for the physical stuffing plan.
Continue planning the shipment
Shipment Workspace
Enter mixed cargo once and carry the same data through volume, chargeable weight, pallets, containers and freight costing.
Methodology & sources
See the formulas, planning assumptions, source links and review dates behind ShipMeasure.
Packaging efficiency
Find the carton-volume threshold where dimensional weight stops exceeding actual weight.