Start with the trailer, not the pallet
Pallet dimensions look arbitrary until you measure the inside of a dry van. A standard 53-foot trailer gives roughly 630 inches of usable floor length and about 98 to 100 inches of interior width at the walls. Every pallet footprint that has ever succeeded commercially is a number that divides neatly into those two figures.
Place 48×40 pallets with the 40-inch dimension across the trailer and you get two side by side, consuming 80 inches and leaving room for the forks, the walls and reality. Run them 15 rows deep at 48 inches each and you consume 720 inches — too long, so in practice loaders mix orientations or accept 26 positions. Turn them so the 48-inch side is across and you fit two with 2 inches to spare and get 30 positions at 40 inches deep. That second arrangement is why the industry settled here.
The Euro comparison that explains everything
A Euro pallet is 1200 by 800 millimetres, which is 47.2 by 31.5 inches. Three of them fit across a European trailer designed around 2.45 metre interior width. Put the same pallet in a North American 98-inch trailer and you can fit three across the 31.5-inch dimension with about 3.5 inches wasted, or two across the 47.2-inch dimension with a wasteful 3.6 inches left over.
Neither arrangement is terrible, but neither is as efficient as the GMA footprint in the trailer that actually exists on American highways. This is the entire reason a metric standard never displaced an imperial one here. It has nothing to do with stubbornness and everything to do with the width of a truck.
What this means when you are choosing a pallet
If your freight stays inside North America and your product does not demand a particular footprint, 48×40 is correct and you should stop thinking about it. The pool is enormous, the used market is liquid, and a Grade A recycled unit costs roughly half of new.
You should deviate when the product itself dictates geometry. Drums want 48×48 so four sit evenly. Beverage wants 42×42 because round cases centre better on a square deck. Nursery stock wants wide deck gaps for drainage. Retail displays want half and quarter footprints so they can roll onto a sales floor. Each of those is a real reason. ‘Our old supplier sent these’ is not.
The overhang trap
The most expensive mistake in pallet selection is accepting a footprint slightly smaller than your product. A load that overhangs the deck by even one inch transfers its weight onto the unsupported edge of the packaging rather than into the pallet structure. Compression strength of a corrugated box drops by a double-digit percentage, and the damage usually appears three handling events later, in somebody else's warehouse.
Measure your loaded unit, not your pallet. If the cases overhang, either change the case pattern or change the footprint. We would rather build you a custom size than sell you a standard one that quietly destroys your product.