Enter your carton size and quantity and see how many fit in a 20 ft, 40 ft or 40 HC container — by volume and by weight, with the limiting factor flagged.
Enter one carton's length, width and height, the weight of a full carton, and how many you have. The calculator returns how many fit in a 20 ft, a 40 ft and a 40 HC box, and how many boxes you need.
It does the packing arithmetic in all six carton orientations rather than assuming you load them the way you typed them, because rotating a carton frequently gains a whole layer.
The payload box is pre-filled with 28,295 kg, the payload of our own 20 ft. For a 40 ft, a 40 HC, or any box you did not buy from us, read the payload off the CSC plate by the right-hand door and type that figure in instead.
Source: ISO 668 nominal internal dimensions. Those differ from manufacturer to manufacturer, and a layer either way is the size of that error.
This is the part most calculators leave out, and it is the part that decides your shipping cost.
Every container load stops for one of two reasons: you run out of space, or you run out of payload. Which one comes first changes the entire plan. If volume stops you, a bigger box helps. If weight stops you, a bigger box is dead freight and you should be looking at more boxes or a denser packing arrangement instead.
The calculator flags which limit you hit and by how much, so you can see whether you are close to the crossover.
The volumes the calculator works from:
20 ft general purpose — 33.2 m³ internal. This is our own box; the figure is ours, not a generic value.
40 ft and 40 HC — published industry reference dimensions. We build the 20 ft box; the 40 ft figures are here for planning.
Internal volumes differ slightly between manufacturers because wall and floor construction differ. If you are planning to the last carton, use the internal figures for the specific box you will be loading.
Internal capacity 33.2 m³, on the box we build. It is set apart from the ISO figures on purpose — one is the standard, one is ours.
| Container | Internal L × W × H | Capacity |
|---|---|---|
| 40 ft GP (1AA) | 12,032 × 2,352 × 2,393 mm | 67.7 m³ (2,390 cu ft) |
| 40 ft HC (1AAA) | 12,032 × 2,352 × 2,698 mm | 76.4 m³ (2,698 cu ft) |
Source: ISO 668, nominal. Internal dimensions are not fixed by the standard and differ from manufacturer to manufacturer. ISO 668 pins the outside of the box and the 30,480 kg gross limit, and leaves the inside to whoever builds it.
No hidden assumptions.
Volume fit is computed by fitting cartons in all six orientations along each axis and taking whole cartons only — no partial cartons, no allowance for compression.
Weight fit is carton weight × quantity against the container payload figure.
What it does not model: pallets, dunnage, load restraint, or the space lost to an irregular stack. A real stow is always a little less efficient than the arithmetic. Treat the result as a ceiling and plan a few per cent below it.
