Planning fundamentals
CBM vs container utilization: why volume alone does not tell you what fits
Understand the difference between total cargo volume and a feasible packing arrangement, with a simple carton example.
Start with the volume calculation
Cubic meters, often shortened to CBM, measure volume. For a rectangular carton, multiply its width, length and height in meters. A carton measuring 0.50 × 0.40 × 0.30 meters occupies 0.06 m³. One hundred identical cartons therefore have a combined box volume of 6 m³.
This calculation is useful for comparing shipment sizes. It does not determine whether those cartons can be arranged inside a particular load space.
A volume total does not describe an arrangement
Consider a simple load space measuring 1 × 1 × 1 meter and two rigid boxes measuring 0.60 × 0.60 × 0.60 meters. Together, the boxes occupy 0.432 m³—less than half of the available volume. Yet the two boxes cannot both fit when their faces must remain aligned with the space: along any axis, putting them side by side would require 1.20 meters.
The same distinction matters with mixed cartons. Dimensions, allowed orientations and the gaps left between items determine how much of the nominal volume is actually usable. A percentage below 100% is not proof that the remaining cargo will fit.
Be clear about the denominator
A nominal cargo-volume ratio is the combined volume of all requested cargo divided by the internal volume of the load space. A packed-volume ratio uses only the volume of cargo actually placed. These are different numbers when some cargo remains unplaced.
Also distinguish the full internal volume from the occupied envelope around the placed cargo. A compact-looking arrangement can still leave difficult gaps, and a high volume ratio does not establish a safe loading plan. Compare the same metric when reviewing different plans.
Check geometry and payload separately
Weight limits are a separate constraint. A load can run out of allowable payload while it still has geometric space. It can also run out of usable geometric space before reaching the payload limit. Neither a CBM figure nor a weight total replaces the other.
Use the actual internal dimensions and rated limits of your equipment. Preset dimensions are starting points; they are not a substitute for checking the equipment you will load.
Use a packing plan to ask better questions
Enter your cargo dimensions, quantities, weights and rotation constraints in StowNexa, then inspect the placement in 3D. Review both packed and unplaced quantities. If something remains out, verify the input and constraints before assuming the shipment is impossible.
StowNexa provides computational packing guidance. It does not certify cargo strength, securing, transport stability, loading sequence or regulatory compliance. Your team must check the physical loading plan and safety requirements.