Container Loading Calculator — How Many Fit
Estimate how many identical cartons fit in a 20ft, 40ft or 40ft High Cube container, and the container's CBM capacity — a fast fit estimate from your carton size, not a 3D load plan.
A 20ft container holds about 33 CBM, a 40ft about 67 CBM and a 40ft High Cube about 76 CBM. To estimate how many cartons fit, divide that usable volume by your carton's CBM for a ceiling, then refine with the orientation-based estimate below (whole cartons fitting along each dimension). This is a capacity/fit estimate, not a 3D bin-packing load plan.
Usable 5.9 × 2.35 × 2.39 m · ~33 m³
Best single-orientation grid — an estimate, not a 3D load plan. Mixed stacking can fit more.
How the estimate works
For each of a carton's six orientations we fit a simple grid into the container's usable length, width and height, and keep the orientation that holds the most. That grid count is realistic for uniform cartons stacked the same way up.
This is a planning estimate, not a 3D load plan. Real loading mixes orientations and accounts for door openings, weight limits and pallet bases — so treat the number as an upper-middle guide, then confirm with your packer.
Usable container sizes
We use typical loadable interiors: a 20ft at about 33 m³, a 40ft at 67 m³, a 40ft High Cube at 76 m³ and a 45ft High Cube at 86 m³. The "volume ceiling" figure is what would fit if cartons poured like liquid — useful only as an absolute maximum.
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Frequently asked questions
How many boxes fit in a 20ft container?
It depends entirely on box size. A 20ft has about 33 m³ of usable space; divide that by your carton volume for a ceiling, then use the orientation estimate above for a realistic figure.
Why is the orientation estimate lower than the volume ceiling?
The volume ceiling ignores geometry — it assumes zero wasted space. The orientation estimate respects that whole cartons must fit along each dimension, which always leaves some gaps.
Does this do 3D container loading or bin packing?
Not a full 3D load plan. 3D container loading software arranges mixed box sizes and orientations into an exact stacking diagram; this tool gives the faster figure most planners need first — how many of one carton fit, by the best single orientation. Use it to size the shipment, then a 3D bin-packing tool for the final stowage diagram.