How to stack boxes on a pallet

The short answer: stack cartons so that every layer has even support, the weight is spread as evenly as possible, and the height and mass of the load do not get in the way of safe transport. In practice that means matching the pattern to the carton dimensions, the pallet type and how the shipment will be secured.

There is no single pattern that suits every case. The same packaging may want one arrangement on a EUR / EPAL 1, another on a 1200 × 1000 mm base and another again on a half-pallet.

Matching the pattern to pallet and carton

A good layout starts with identifying the carrier, not the carton. A 1200 × 1000 mm footprint can belong to a marked EPAL 2 or to a cheaper build with quite different capacity - the difference is explained in the article on the industrial pallet. Always plan layers against a measured base and the documentation for that specific pallet.

From there, three inputs drive the layout: pallet dimensions, carton dimensions and the permitted height of the whole load. Only then can you decide between a column pattern, an interlocked one or a mix. With heavier cartons it also matters where the centre of gravity of each layer ends up.

Rules that make the load stable

A stable pallet starts with an even base. Cartons should not overhang the edge without control - every overhang raises the risk of layers shifting during driving, handling or braking. If the pattern demands it, change the carton orientation rather than leave an unsupported corner.

Heavier packaging goes low, lighter high. That keeps the centre of gravity down and limits rocking. Keep layers as flat as you can, because an uneven surface lets cartons slide and pulls the whole block apart. Cardboard slip sheets help stabilise layers, particularly when cartons have slippery surfaces or differ in strength. Stretch film, straps and corner protectors then cut the risk of edge damage - they reinforce good stacking, they do not replace it.

• Build the first layer as full and as flat as possible.
• Check that the following layers do not creep out of line with the base.
• Confirm the securing does not squeeze the load hard enough to deform it.

Three worked layer patterns

Pattern 1 - a 400 × 300 mm carton on a EUR / EPAL 1. Set the long side across the pallet and one row takes 4 pieces (4 × 300 mm = 1200 mm); the 800 mm width takes 2 rows of 400 mm. The layer is 8 cartons with full coverage and no overhang.

Pattern 2 - a 600 × 400 mm carton on the same pallet. Two cartons lengthwise (2 × 600 mm = 1200 mm) and two rows across (2 × 400 mm = 800 mm) give 4 pieces per layer, again with full coverage.

Pattern 3 - the same 600 × 400 mm carton on a 1200 × 1000 mm base. Three cartons set short-side-along (3 × 400 mm = 1200 mm) fill a 600 mm deep band, and the remaining 1200 × 400 mm band takes 2 more, rotated. The mixed layer is 5 cartons and closes the full footprint - which is exactly why rotating part of a layer can add a whole piece.

How many cartons fit, and on what it depends

There is no honest single number without the packaging dimensions. Carton size, rotation within the layer, number of layers and permitted load height all decide it. From the patterns above: the same EUR / EPAL 1 takes 8 cartons of 400 × 300 mm or 4 of 600 × 400 mm per layer, which over five layers is 40 or 20 pieces.

What limits the number of layers is not geometry but weight and packaging strength. At 15 kg per carton, five layers of 8 is already 600 kg - still well under the 1500 kg safe working load of an EPAL 1, but the bottom layers carry everything above them. So count cartons per layer first, then the accumulating weight, then total unit height. The full method is in how many boxes fit on a EUR pallet.

The most common mistakes

Uneven layers, first of all - they let cartons shift and weaken the whole pallet even when the individual boxes are strong. Second, poor weight distribution: concentrate the mass on one side and the pallet loses stability quickly. Third, no edge or layer protection, which matters most on taller loads and shipments that pass through several handling points.

• Don't leave accidental voids inside the stack if they weaken the base layer.
• Don't build the pallet taller purely to fit more cartons on.
• Don't assume one pattern will suit every carton format.