Cubestow docs
Everything about planning a load in Cubestow. Five minutes to read; most people only need the first two sections.
1. Getting started
- Choose the container or vehicle. Pick a preset (20GP, 40HC, 13.6 m trailer, EUR pallet …) or choose Custom and type the inner length, width, height and payload. Presets use typical inner dimensions — check your carrier's spec if the load is tight.
- Add cargo. One row per item type: name, L × W × H, weight, quantity. Use the unit selectors (mm / cm / in, kg / lb) before entering numbers. Or click Paste from Excel and paste rows; a header row is recognised.
- Set rules per row (see below), choose the mode, press Calculate load plan.
Your project autosaves in the browser. Use Save project for a file you can reopen or send to a colleague, or Copy share link — the link contains your inputs; nothing is uploaded anywhere.
2. Cargo rules
| Rule | Options | What it means |
|---|---|---|
| Rotation | Any · Keep upright · Fixed | Any allows all six orientations. Keep upright keeps the item's height vertical and only turns it on the floor plane ("this side up"). Fixed loads it exactly as entered. |
| On top | Allowed · Nothing · Max load | Allowed: anything may be stacked on it. Nothing: fragile or top-load-only — no item may rest on it, and it will not be slid under an already-loaded box. Max load: the maximum weight the item can carry on top; weight is propagated down through whole stacks. |
| Floor only | tick | Must stand on the container floor: heavy machinery, drums, wheeled cargo, pallets that must be reachable by forklift. |
| Stop | 1, 2, 3 … | Delivery stop. Stop 1 is unloaded first, so it is loaded last (nearest the door). Items for later stops are loaded deeper. Cubestow keeps stops in strict blocks along the length so nothing has to be moved to reach an earlier drop. |
Global rules: Minimum support (default 80%) is the share of each box's base that must rest on the floor or on boxes directly beneath. 100% is the safest for fragile cargo; 60% packs tighter with mixed sizes. Prefer balanced centre of gravity nudges the optimiser toward plans whose weight sits near the middle of the container.
3. Modes
Fill up to N of this container loads as much cargo as fits into the containers you have, in order, and lists what is left over. Use as few containers as possible keeps opening containers of the chosen type until everything is loaded (Pro; the free plan is limited to one container).
4. Reading the plan
- Coordinates. Positions are measured from the far wall (x), the left wall (y) and the floor (z). Hover any box to see them.
- Loading sequence. Step 1 is the first box in. Later stops load first; within a stop the plan runs from the far wall towards the door, bottom to top, left to right. Press Play to watch it.
- Volume / payload bars. Utilisation against the container's inner volume and max payload. A red payload bar means the plan exceeds the limit (only possible if you edit the payload after solving).
- Centre of gravity. Expressed as a percentage along the length, across the width and up the height. 50% along the length means centred between the far wall and the door.
- Cargo reaches. How far from the far wall the load extends — the rest is free floor at the door for bracing or last-minute items.
- Self-check. Every plan is re-validated independently of the optimiser: no overlaps, every box inside the container, support ratio met, nothing on non-stackable items, weight limits kept, stops in order. You will see a green tick or an explicit list of issues.
5. Exports
- Image (PNG) — the current 3D view at 2000 px, for chat or email.
- PDF load plan (Pro) — summary page plus one page per container: 3D snapshot, statistics, manifest and the grouped loading sequence with positions.
- Excel (Pro) — Summary, Cargo and one Placements sheet per container with the exact x / y / z, size, weight and step of every piece — ready for a WMS or a pick list.
- Save / Open project — a small JSON file with all inputs. Copy share link — same content in a URL.
6. Pro licences
Buy Pro on the pricing page (Stripe checkout). Your licence key is shown the moment payment completes, with a one-click button that opens the planner already activated; bookmark that page — it always shows your key. On another device, click Activate Pro and paste the key. A licence is per user and works on all your devices. Pro is checked against your subscription about once a week and keeps working offline for three weeks in between. Cancel or change your card any time via Manage billing (Stripe's portal); 14-day money-back guarantee.
7. How the engine works
Container loading is NP-hard, so Cubestow — like every load planner — uses heuristics, but careful ones:
- Empty maximal spaces. The container starts as one empty space. Every placement splits the spaces it touches into the largest remaining rectangular gaps, so the engine always knows exactly where something could still go.
- Wall building. Identical items are placed as rectangular blocks (columns, rows and walls), which packs tighter and produces load plans that look like real loads.
- Back-bottom-left. Candidate positions are scored so cargo settles against the far wall, the floor and the left side, keeping the free space in one usable piece near the door.
- Constraints at placement time. Support share, stacking permissions, weight-bearing (propagated down through stacks), orientation, payload and delivery-stop blocks are all checked before a box is committed — not patched afterwards.
- Multi-start search. Many item orderings and placement rules are tried within the time budget — bigger-first, taller-first, heavier-first, floor-only-first, and randomised variations of the best plan found so far. The best plan by loaded volume, then fewest containers, then compactness and balance, wins. The same inputs and seed always give the same plan.
On standard weakly-heterogeneous test instances the engine reaches roughly 85–93% volume utilisation within three seconds in a browser. Longer optimisation times (Pro) let the randomised search run further.
8. Tips
- Enter the outer dimensions of cartons and pallets (pallet base plus load).
- If something "should fit" but doesn't, try 60% support, allow rotation, or check whether floor-only items are eating the floor.
- For a truck with axle limits, watch the centre of gravity along the length and use the balance option; full axle-load calculation is on the roadmap.
- Change the seed to get a different but equally valid plan when you want alternatives.
Changelog
1.1 — 367 calculated fit guides (pallets, cartons, drums, IBCs and appliances in every container, trailer, truck and on pallets), each opening in the planner; floor-only items are no longer stacked on copies of themselves.
1.0 — first public release: containers, trucks, pallets; stacking / orientation / floor-only / max-load / delivery-stop rules; minimise-containers mode; 3D viewer with loading sequence; PNG, PDF, Excel, JSON exports; share links; Pro licensing.
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