Pallet stacking patterns explained
The two main ways to stack cartons on a pallet are column stacking, where every box sits directly on the box below, and interlocking (brick) stacking, where each layer is rotated or shifted so boxes overlap the seams below. Column stacking keeps the full compression strength of the boxes; interlocking makes the load more stable but can reduce box strength by up to about half. In trailers and containers, pallets are loaded straight, turned or in a pinwheel pattern to fit the most pallets.
Carton stacking patterns on a pallet
| Pattern | How it works | Best for | Watch out for |
|---|---|---|---|
| Column (block) | Every layer is the same; box corners line up vertically. | Heavy or fragile goods in corrugated cartons; maximum stacking strength. | Columns can lean apart; use stretch wrap, corner boards or a top sheet. |
| Interlocking (brick) | Each layer is turned 90° or shifted so boxes bridge the gaps below. | Light cartons where stability matters more than strength. | Box corners no longer sit on corners, so compression strength drops. |
| Pinwheel | Boxes are arranged around the centre, alternating direction each layer. | Square pallets and box sizes that don't divide the pallet evenly. | Can leave a hole in the centre; less strength than column. |
| Row / split row | Rows of boxes in one direction, alternate rows turned. | Filling odd gaps with one carton size. | Uneven support; check the top layer is level. |
Column or interlocking: which is better?
Corrugated boxes carry most of their load in the corners and side walls. In a column stack, those walls sit directly on the walls below, so the stack keeps nearly all of the box's compression strength. Interlocking moves the walls over the box tops below, which can cut stacking strength sharply, by up to about 50% in packaging tests. Overhang beyond the pallet edge weakens boxes too. A good rule:
- Use column stacking for anything heavy, fragile or stacked high, and stabilize it with stretch wrap, corner boards and a top sheet.
- Use interlocking only for light, strong or self-supporting goods, or interlock just the top one or two layers to tie the load together.
- Never let cartons overhang the pallet edge, and avoid large underhang that leaves the load loose.
Our pallet calculator finds the layer that fits the most cartons and shows it in 3D. For carton counts by size, see how many boxes fit on a pallet.
Pallet loading patterns for trailers
| Pattern | How pallets face | 53 ft trailer | 48 ft trailer |
|---|---|---|---|
| Straight | 48 in side along the trailer, two across | 26 | 22–24 |
| Pinwheel | One pallet straight and one turned in each row, alternating sides | 28 | 24–26 |
| Turned | 40 in side along the trailer, two across | up to 30 | up to 28 |
Straight loading is quickest and works with two-way pallets. Turned loading needs four-way pallets and enough trailer width. Pinwheel loading (sometimes called a block pattern) fits more pallets when turning both is too tight, and the rows lock against each other so the load shifts less. Weight often ends the plan before floor space does: see pallets on a 53 ft trailer.
Pallet patterns in shipping containers
Containers are narrower, about 2.35 m inside. US pallets usually go two across. Euro pallets are loaded in mixed rows, some lengthwise and some crosswise, to use the width. A 20ft takes 11 Euro or 9 US pallets in one layer; a 40ft takes 20 US pallets and 23–24 Euro pallets. See pallets in a 20ft container and pallets in a 40ft container.
Frequently asked questions
What is the strongest pallet stacking pattern?
Column stacking, because each box sits directly on the walls of the box below and keeps its full compression strength.
What is interlocking stacking?
A pattern where each layer is rotated or shifted so boxes overlap the seams of the layer below, which makes the load more stable.
What is a pinwheel pallet pattern?
On a pallet, boxes are arranged around the centre in alternating directions. In a trailer, each row has one pallet straight and one turned, alternating sides.
How many pallets fit in a 53 ft trailer with a pinwheel pattern?
Typically 28 standard 48 × 40 pallets, between 26 loaded straight and up to 30 turned.