Pallet stacking patterns: grid, interlock, pinwheel, column and rotated layers

There are only a handful of ways to arrange rectangular cartons on a rectangular deck, and every warehouse in the world uses some mix of the same five. Three of them, grid, split-row interlock and pinwheel, are what the PalletTool calculator evaluates in both carton orientations for every plan, keeping whichever fits the most cartons per layer with no overhang. The other two, column stacking and rotated layers, are ways of using the patterns you have, layer by layer, rather than layouts of a single layer.

The rule the calculator follows is simple and worth knowing by heart: count first, lock second. The pattern that fits the most cartons per layer wins, and when two patterns tie on count, the interlocking one wins, because it holds the load together at no cost in cartons.

Grid

A grid is the layout everyone draws first: straight rows and columns, every carton facing the same way. The calculator tries it in both orientations, long side along the pallet's length and long side across it, and keeps the better one.

When it wins. Whenever the carton's dimensions divide the deck cleanly. A 600 × 400 mm carton on a 1200 × 800 mm EUR pallet is the textbook case: the footprint tiles the deck exactly and nothing else can fit more.

What it costs. Nothing in count when it wins, but a plain grid has no lateral lock. Every layer sits in identical columns, so the load's stability comes entirely from stretch wrap, strapping or the cartons' own friction.

Stability and compression. Column-aligned grids put carton corners over carton corners, which is the strongest way to carry vertical load. Grid layers stacked without mirroring are effectively column stacking, see below.

Split-Row Interlock

The split-row pattern runs most of the layer in one orientation, then turns the remaining strip 90°. Because the layer is no longer symmetric, alternate layers can be mirrored, and the seams of one layer land on the solid cartons of the next, like brickwork.

When it wins. When one orientation leaves a strip of deck too narrow for another full row but wide enough for cartons turned sideways. That reclaimed strip is pure extra count.

What it costs. Sometimes nothing, it simply beats the grid. When it ties with a grid, the calculator still prefers it, because the mirrored layers interlock and the grid's do not.

Stability and compression. Interlocking is the point: mirrored layers tie the load together and resist shifting in transit. The trade-off is that fewer cartons sit corner-over-corner, so more of the vertical load passes through carton faces and edges, which are weaker than corners. For light and medium cartons this trade is almost always worth it; for very heavy or fragile cartons, column alignment matters more.

Pinwheel

A pinwheel places four cartons rotating around the center, two lengthwise and two upright, like a windmill. It exists because of one geometric fact: it works whenever the carton's length plus width fits within both deck edges.

When it wins. On decks where straight rows strand space, classically the 1200 × 1000 mm pallet with cartons in the 550-600 × 380-450 mm range. The calculator's worked example, a 580 × 410 mm glove case on a Standard pallet, fits 4 per layer as a pinwheel where plain rows manage less.

What it costs. A pinwheel is always exactly 4 cartons per block, so on decks where a grid fits 5 or more, the pinwheel loses and the calculator discards it.

Stability and compression. Like the split-row, pinwheel layers can be mirrored so layers lock. The center of a pinwheel often has a small void; the load carries around it, which is fine for stiff cartons and worth watching for soft ones.

Column stacking

Column stacking is not a layer layout but a stacking decision: repeat the same layer, unmirrored, so every carton sits exactly on the one below, corner-over-corner all the way up.

When it wins. When carton strength is the limit, not space. Corrugated cartons carry vertical load overwhelmingly through their corners and edges, so aligned columns preserve the most stacking strength, which matters for heavy loads, tall stacks and long storage.

What it costs. Stability. Columns have no mechanical connection to each other; without stretch wrap or strapping the stack can split into towers. Count per layer is unchanged, it is the same layer repeated.

Rotated layers

The other classic stacking decision: keep each layer uniform, but turn alternate layers 90°. It only works when the layer looks similar in both orientations.

When it wins. As a simple way to tie a load together when the pattern itself has no interlock, typically square-ish footprints where both orientations fit the same count.

What it costs. When the two orientations do NOT fit the same count, the rotated layer is the smaller one, and you pay for stability in cartons. It also gives up corner alignment, like any interlock.

Comparison

The calculator applies the first three automatically, and the right stacking decision on top of them depends on your cartons: light cartons on short hauls favor interlock, heavy cartons in tall storage favor column alignment. Try your own dimensions, or browse the verified capacity pages for common carton sizes.