Formula
Each internal side is divided and rounded down:
cartons = floor(internal length / carton length) × floor(width / width) × floor(height / height)
The internals used for planning are 589.8 × 235.2 × 239.3 cm for a 20-foot, 1,203.2 cm long for a 40-foot, and 269.8 cm high for a high cube. CBM alone does not check this fit.
Assumptions
- The carton orientation is the one you enter.
- No dunnage or pallet eats into the internal box.
- The figures are planning internals, not a particular ship's survey.
Worked example
Fifty by 40 by 40 centimeter cartons fit 275 in the 20-foot planning box.
Input definitions
- Internal box
- The usable length, width, and height inside the container, before lashing and uneven cargo.
Limitations
Door openings, weight limits, and a mixed cargo will hold fewer cartons than this grid. The carrier's internal sheet overrides these planning numbers.
Questions
Why 275 in a 20-foot?
589.8 divided by 50 is 11 along. 235.2 divided by 40 is 5 across. 239.3 divided by 40 is 5 high. Eleven times five times five is 275.
Is this the same as dividing CBM?
No. Dividing cubic meters ignores a carton that does not fit the leftover strip. This page keeps that strip empty.