The six, side by side

Footprints to one scale, length by width in inches (the Euro pallet is 800 x 1200 mm, about 31.5 x 47.2 in). Stringer length is the first number.

Floor count in a 53 ft trailer, one layer, the better of the two orientations
Size	Metric	On the floor	Where it turns up
48 x 40	1,219 x 1,016 mm	30	Grocery, retail, most distribution
42 x 42	1,067 x 1,067 mm	30	Beverage and paint
48 x 48	1,219 x 1,219 mm	26	Drums and totes
48 x 45	1,219 x 1,143 mm	28	Automotive parts
48 x 42	1,219 x 1,067 mm	30	Chemical and drink loads
800 x 1200 mm	800 x 1,200 mm	40	Imported goods on Euro pallets

The floor counts assume an inside floor of 630 x 98 inches, one layer and no overhang; pallets per trailer shows the working. Real trailers vary, so treat the table as a way to compare sizes and not as a promise about any load.

There is no single official size

No universally accepted standard exists for pallet dimensions. What exists is habit. The 48 x 40 pallet is the most common wood pallet size in North America and accounts for 30% of the new wood pallets made in the United States, and ISO accepts the 48 x 40 specification as the North American standard. Every other size is a response to a particular load.

Choosing from the load

Start with what the pallet will carry, not the pallet.
Measure the carton or crate footprint and compare it to the deck.
Ask what the receiving dock expects; docks set up for 48 x 40 may refuse others.
If you ship through a trailer, check the count in the table before you commit.

A request that names a size gets read at once. One that says "regular pallets" gets a question back, and the question is nearly always "which size?".

48 x 48

A 48 x 48 pallet is the 48 x 40 stretched square, often used in the chemical sector, where drums and totes sit four to a deck.

A 55-gallon drum stands about 23 inches across, so four fit a 48 x 48 deck with a little to spare, and a tote 48 inches on a side fits it exactly. Drum and tote sizes vary by maker, so measure yours. Racking built for 48 x 40 seldom accepts a square pallet unless the beams are spaced further apart; storing square pallets on the floor avoids the problem.

Name the size as 48 x 48 with the count and grade, and say whether the load is wet, oily or chemical, since stained wood is not for food docks. A block build is the usual pairing, because forks can reach a drum load from any face.

48 x 42

The 48 x 42 pallet, 1,219 x 1,067 mm, ranks fifth in North American production, ahead of the 48 x 45. It is the 48 x 40 with two more inches across the deck, enough to carry a square-ish layer of cartons or four small drums without overhang, and chemical and drink distributors ask for it by name.

A rack built for 48 x 40 often holds it too, since the stringer length is the same, but the extra two inches overhang a beam where the rack was built to the tighter spec. Say 48 x 42 clearly, because a typo for 48 x 40 is common, give the grade and count, and say whether the pallets carried chemicals, which matters to the next owner. Keep 48 x 42 out of a 48 x 40 stack unless the stack is labelled as a mixed load and counted size by size.

Euro 800 x 1200

The Euro pallet is the European standard, 800 x 1200 mm or about 31.5 x 47.2 inches, so it is narrower than the American 40 inches across the stringers. It reaches New England under imported goods from places that do not use 48 x 40.

At the dock the problem is not the pallet but the racks. American racks are cut for 48 x 40, and a Euro pallet can sit in them only if the beams support it along its long side. Imported Euro pallets should carry the ISPM 15 stamp, and one without it is a problem if it is going back out; see reading the stamp.

Give the size in millimetres, with the count, the condition, whether the stamp is present and the town. Buyers for Euro pallets are fewer than for 48 x 40, so a seller should expect a specific match, not a broad market.