Column, split and pinwheel: what the three patterns mean
A column pattern puts every box the same way, corners stacked on corners. It holds the most weight and is the fastest to build, but the stack can slide sideways. A split pattern fills most of the pallet one way and the leftover strip the other way, which often adds a box or two. A pinwheel turns four blocks of boxes around the centre so each layer braces itself; it usually fits a box or two fewer than columns and is the pattern warehouses pick when the load has to survive a bumpy truck. Interlocking turns or mirrors every second layer so the seams do not line up; a layer of plain columns lands on its own seams, so the sheet says when interlock is not possible. The calculator shows the count for all three, marks the best one, and lets you force a pattern.
Height, weight and overhang limits
Carriers and fulfilment centres measure the load with the pallet. Amazon FBA takes single pallets up to 72 in tall and 1,500 lb, with no overhang past the 40 x 48 in footprint. Most LTL carriers accept up to about 96 in and 2,000 to 2,500 lb per pallet, and the pallet itself adds 5 to 6 in and 30 to 50 lb. Dense goods such as supplements or hardware hit the weight cap before the height cap, so the sheet always says which limit stopped the stack. Overhang adds boxes but many receivers refuse it; set it per side and the drawing shows what sticks out. Rules change, so the limits here carry a date and a link.