Choose which rectangle the volume describes
A planner has a 1200 by 800 mm base, a 1500 mm total-height budget, and a carton plan. Three useful volumes can be calculated, but they answer different questions. The occupied outer load is one prism. The permitted-height reference is another prism. The sum of external carton volumes is an inventory-derived quantity. Labeling all three simply “pallet CBM” makes the record difficult to audit and can conceal unused vertical space.
This fictional calculation uses a base height of 144 mm and identical cartons 400 by 300 by 250 mm. Horizontal rotation is allowed, with zero added gaps and zero edge clearance. The dimensions are supplied scenario inputs, not a statement about a base rating or a permitted stacking operation. The footprint engine finds eight cartons per layer. The height budget permits five complete layers, so the modeled count is forty.
Follow the complete-layer height through the calculation
Five carton layers occupy 5 × 250 = 1250 mm above the base. Adding 144 mm gives a planned overall height of 1394 mm. The remaining 106 mm below the 1500 mm reference is unused headroom: it does not become a fractional sixth layer. A sixth complete layer would require 1644 mm overall. This is why multiplying the base footprint by the entered maximum height overstates the planned enclosing volume in this example.
The footprint is 1.2 × 0.8 = 0.96 square metre. Planned volume is 0.96 × 1.394 = 1.33824 cubic metres. Reference volume is 0.96 × 1.5 = 1.44 cubic metres. Each carton is 0.4 × 0.3 × 0.25 = 0.03 cubic metre, giving an external carton sum of 40 × 0.03 = 1.2 cubic metres. These products are geometric calculations, with no product density or mass assumption.
| Quantity | 1500 mm height budget | 1300 mm height budget |
|---|---|---|
| Complete layers / cartons | 5 / 40 | 4 / 32 |
| Planned total loaded height | 1394 mm | 1144 mm |
| Planned outer volume | 1.33824 m³ | 1.09824 m³ |
| Maximum-height reference | 1.44 m³ | 1.248 m³ |
| Sum of external carton cubes | 1.2 m³ | 0.96 m³ |
| Cargo stack envelope | 1.2 m³ | 0.96 m³ |
Run both budgets with unchanged cartons
Use the 1500 mm build scenario and the 1300 mm build scenario. Read the planned cube and reference cube as separately named outputs. The second run loses a complete layer; the planned envelope falls by 0.24 m³ while the reference falls by only 0.192 m³. Those different changes are correct because one quantity follows integer layers and the other follows a continuously changing height budget.
For an independent volume check, open known dimensions 1200 by 800 by 1394 mm. It returns the same 1.33824 m³ planned envelope without producing TI, HI, or a carton count. Known mode is appropriate once the outer dimensions are already available. It does not reconstruct the reason that a plan arrived at 1394 mm or establish whether the measured load matches that plan.
Interpret the equality between carton sum and cargo envelope
The carton sum and cargo stack envelope both equal 1.2 m³ because this particular zero-gap layer tiles the footprint and every layer is complete. That equality is a consequence of the selected geometry. It is not a definition that holds for all pallets. A layer with unused footprint, an incomplete top layer, or space between cartons can have a smaller external carton sum than the rectangular cargo envelope.
The base adds 0.96 × 0.144 = 0.13824 m³ to the enclosing prism. This is not the volume of solid base material. It is the rectangular region below the carton stack across the full footprint, including any openings. The 1.33824 m³ outer volume therefore remains larger than the 1.2 m³ carton sum even with perfect footprint tiling. Naming that difference prevents it from being mistaken for extra cartons or packaging waste.
Reproduce and retain the input record
Inputs: mm; build mode, maximum-height mode; base 1200 × 800 × 144; cases 400 × 300 × 250; rotation allowed; gap and clearance zero. Compare maximum overall heights 1500 and 1300. Results: TI 8; HI 5 or 4; counts 40 or 32; loaded heights 1394 or 1144. Mass, sheet thickness, partial layers, and measured projections are not supplied.
Select an output for the receiving task
For a dimensional record describing the completed planned load, use the planned loaded envelope and state that it is predicted from cartons. For a comparison of how much of a height allowance is used, retain the reference prism too. For a tally of case external volumes, retain the carton sum and count. None of those choices independently establishes which volume a service provider uses for charging; that depends on the applicable definition.
Before substituting measured dimensions, check whether the outer footprint stayed 1200 by 800. Any bulge or projection changes the measured enclosing rectangle even if the base dimensions remain unchanged. Interlayer sheets or a top cover can also change measured height without changing carton count. These inputs need separate measurement or a stated manual adjustment, because the build example models identical case heights and the base, rather than every possible added component.
The forty-carton plan also offers a reverse height check: divide its 1.2 m³ carton sum by the full 0.96 m² footprint to obtain 1.25 m, then add the stated 0.144 m base. This works here because the modeled layers tile that footprint without added spaces. It would not be valid to reconstruct cargo height from the carton sum this way for an incompletely filled footprint. Save the tiling assumption if using that reverse check.