Calculator inputs
Use auto fit to compare orientations, or set cartons per layer manually.
Example data table
| Scenario | Pallet Size | Carton Size | Boxes/Layer | Allowed Layers | Overall Height | Gross Weight |
|---|---|---|---|---|---|---|
| Standard warehouse lane | 1200 x 1000 x 144 mm | 400 x 300 x 250 mm | 9 | 6 | 1659 mm | 457 kg |
| Lower trailer opening | 1200 x 1000 x 144 mm | 400 x 300 x 220 mm | 9 | 7 | 1702 mm | 529 kg |
| Manual mixed SKU layer | 1200 x 800 x 144 mm | Mixed cartons | 6 | 5 | 1416 mm | 295 kg |
Formula used
1) Boxes per layer
Auto mode checks both carton orientations and keeps the larger result.
- Standard fit = floor(pallet length / carton length) x floor(pallet width / carton width)
- Rotated fit = floor(pallet length / carton width) x floor(pallet width / carton length)
- Boxes per layer = max(standard fit, rotated fit)
2) Height-limited layers
The calculator removes pallet height and top clearance before stacking cartons.
- Usable height = max height - pallet height - top clearance
- Height-limited layers = floor((usable height + interlayer thickness) / (carton height + interlayer thickness))
3) Weight-limited layers
The load must stay below the allowed gross stack weight.
- Net load allowance = max gross weight - pallet tare weight
- Weight-limited layers = floor(net load allowance / (boxes per layer x carton weight))
4) Final stack outputs
The smallest valid layer limit becomes the final answer.
- Final layers = min(height limit, weight limit, requested layers if entered)
- Total cartons = final layers x boxes per layer
- Load-only height = (layers x carton height) + ((layers - 1) x interlayer thickness)
- Overall height = pallet height + load-only height
How to use this calculator
- Enter pallet footprint, pallet height, and empty pallet weight.
- Enter carton dimensions and carton weight for one selling unit or case.
- Set the maximum allowed overall height and gross stack weight from your warehouse, trailer, or rack rule.
- Add interlayer thickness and top clearance if slipsheets, separators, or safety gaps are required.
- Choose auto best fit to compare carton orientation automatically, or manual mode for mixed-SKU layouts.
- Optionally set requested layers to test a planned stack against the real limits.
- Press Calculate stack to show the result above the form, then export it to CSV or PDF.
Frequently asked questions
1) What does pallet stack height mean?
It is the full loaded height from the floor to the top of the stacked unit. This tool includes pallet height, carton layers, and optional interlayer thickness to estimate that final dimension.
2) Why does the calculator compare two carton orientations?
Many cartons fit differently when rotated ninety degrees on the pallet footprint. Comparing both layouts helps you maximize cartons per layer without changing carton dimensions or pallet size.
3) What is top clearance reserve?
Top clearance is an intentional safety gap below your height limit. It helps protect loads from rack beams, trailer roofs, stretch wrap bulge, or forklift handling variation.
4) When should I use manual boxes per layer?
Use manual mode for mixed cartons, nested items, custom pack patterns, or real warehouse layouts that cannot be represented by one simple carton length and width.
5) Does this tool account for pallet weight?
Yes. The calculator subtracts pallet tare weight from the gross limit first, then checks how many carton layers remain possible within the allowed stack weight.
6) Why can height allow more layers than weight?
If each carton is heavy, the gross stack weight may reach its limit before the stack reaches the physical height limit. The tool reports both constraints separately.
7) What does cube utilization show?
Cube utilization compares total carton volume with the rectangular load envelope created by the pallet footprint and stacked load height. Higher percentages usually indicate tighter volumetric use.
8) Can I use this for rack storage and trailers?
Yes. Enter the correct height and gross weight limits for your rack bay, trailer door, container, or process rule, then review the remaining headroom and capacity.