The customer says they have 500 cartons and asks whether it is one 40ft or two. Guess wrong and you either quote a container they do not fill or promise space that is not there. The fit depends on carton size, orientation, and often the weight before the volume.
Enter one carton and the calculator does all three container types at once.
CargoEZ turns cargo details into load plans, volume and weight utilization, and rolls them straight into quotes and bookings. Built for freight forwarders.
How the fit is worked out
The calculator takes your carton and finds the orientation that fits the most units. For each way the carton can sit, it divides the container’s internal length, width and height by the carton’s three sides, rounds each down to a whole number, and multiplies. The best of those six orientations is the count you see.
Cartons per axis = floor(container side ÷ carton side)
Fit = length-count × width-count × height-count (best orientation)
This is a same-orientation estimate, which is how most forwarders quote. Real loading can mix orientations and squeeze in a few more, and it can also lose some to bracing and pallet gaps, so treat the number as a tight planning figure rather than a loading diagram.
Volume versus weight, and which one bites first
A container has two ceilings. One is space, the other is payload. Light, bulky cargo hits the volume ceiling and the box looks full while it is nowhere near the weight limit. Dense cargo does the opposite. A 20ft standard caps around 28 tonnes of payload, so a carton at 150 kg fills the weight before it fills half the space.
The calculator checks both and tells you which one limits the load. When it says weight limited, stacking more cartons is not an option, and you either split the shipment or move to a 40ft to spread the weight. That single flag stops the classic mistake of quoting a volume-based count on heavy freight.
Worked example
A 60 by 40 by 40 cm carton weighing 20 kg.
| Container | Cartons | Fill | Load weight |
|---|---|---|---|
| 20ft Standard | 225 | ~65% | 4,500 kg |
| 40ft Standard | 500 | ~71% | 10,000 kg |
| 40ft High Cube | 600 | ~75% | 12,000 kg |
All three are volume-limited, which is normal for cartons this light. Ship 500 of them and the calculator shows you need one 40ft, not two. For the raw cubic meters and chargeable weight behind these numbers, use the CBM calculator. More tools are in the freight forwarding calculators section.