Double stacking pallets: which containers and trailers have the height

Two layers of pallets fit when the inside height is at least twice the loaded pallet height. Across 17 closed units that ceiling runs from 1,131 mm per unit in a 20ft reefer container to 1,470 mm in a mega trailer, and at a 1.4 m unit height only the mega trailer still takes two layers.

By Oliver Bennett · Published 29 October 2026 · Data as of 27 October 2026, from spec sheets retrieved that day

Floor space is only half of a pallet plan. If the goods can take a second layer, the height of the box decides whether it fits, and a few centimetres decide between a full second layer and none at all. This guide works the geometry out for the 17 closed containers, trailers and trucks on PalletSpec, using the smallest inside height any source publishes for each.

The rule is simple. Two layers fit when the inside height is at least twice the height of one loaded pallet, the pallet plus the goods on it. Three layers need three times. Everything below follows from dividing one number by another and rounding down.

The ceiling for two layers

The range is wide. The lowest ceiling belongs to the 20ft reefer container, where two layers fit only while each loaded pallet stays at or under 1,131 mm. The mega trailer is the roomiest, with 2,940 mm inside and room for two layers of up to 1,470 mm each. It is also the only unit here where a third layer is even thinkable: three layers of up to 980 mm.

The pallet itself counts. A EUR1 is 144 mm high and a 48×40 about 141 mm, so in a standard 40ft container, with its 2,390 mm ceiling, two EUR1 loads leave 1,051 mm for the goods on each pallet. In a 40ft high cube the same figure is 1,203 mm.

Layers at five unit heights

Most shippers know their unit height roughly, so the table gives the layer count for five common values.

At one metre every unit takes two layers. At 1.2 m the 20ft container, 40ft container, 20ft reefer container, 20ft open top and 40ft open top drop to one. At 1.3 m, 11 of the 17 still take two. At 1.4 m only the mega trailer does: the North American dry vans in the data are 2,794 mm high inside, 6 mm short of two 1.4 m units.

That last case shows how sharp the edges are. A shipper who can bring the unit down from 1,400 to 1,390 mm doubles what a 53 ft van carries. The same is true of the standard 40ft container at 1,200 mm: 25 EUR1 pallets in one layer, 50 at 1,100 mm.

What fits through the door

Every container in the data has a rear door opening no higher than the inside height. A single tall unit has to pass that opening, so it is the door, not the roof, that caps it. The largest difference is in the 45ft high cube: 2,697 mm inside, but a door opening of 2,582 mm. For two layers the door hardly matters: a unit short enough to stack twice is far lower than any door opening in the table. Our sources give no door opening for the 53 ft dry van, 48 ft dry van and 26 ft box truck, so their door column is left blank.

Stacked totals for EUR1 and 48×40 pallets

At a 1.2 m unit height, here is what the floor count turns into once the second layer is added.

The largest stacked loads are on the North American vans and the European trailers, which all take two layers at this height. In the 40ft high cube the second layer turns 25 EUR1 pallets into 50. At 1.4 m the 13.6 m curtainsider falls back to 34 while the mega trailer keeps 68.

What this does not cover

These are height counts only. Whether a load can carry another one on top depends on the goods, the packaging and the pallet, and none of that is modelled here. Weight limits for the unit and the road also still apply, however many layers fit. To try your own unit height, set it in the load planner; the layer count and the stacked total change with it. For the floor side of the same question, see loading metres explained.

More guides: Why some pallet and container pairs waste floor space · How to use the pallet load planner · Loading metres explained, pallet by pallet · How many pallets fit: every pallet in every container and trailer · Pallet dimensions in inches · All guides