Shipping container door dimensions

A standard dry container's door opening is 2,340 mm wide and 2,280 mm high, 112 mm lower than the inside. The high cube door is 305 mm taller at 2,585 mm, while in reefers the door is as wide as the insulated interior and only 8 mm lower in the high cube reefer.

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

A container is only as useful as the hole you load it through. On most closed boxes the rear doors are a little smaller than the space behind them, because the door frame and its seals take up room. For most cargo the difference never matters. For tall machinery, crates built to the inside height or a forklift mast, it decides what goes in.

Door opening against inside size

The table sets the typical door opening of each container with doors against its typical inside width and height. The last two columns are the millimetres lost at the door.

Width is almost never a problem. The narrowest typical door in the data is 2,290 mm, and the largest pallet side on PalletSpec is 1,220 mm, so any single pallet goes through any door either way round. On the standard dry boxes the door is just 10 mm narrower than the walls behind it.

Height is where the door bites. On the standard 20ft and 40ft dry boxes the opening is 112 mm lower than the inside, and on the 45ft high cube the gap is 116 mm. A crate that would stand comfortably under the roof can still hit the door header on the way in.

The high cube door

A 40ft high cube is one foot taller outside than a standard 40ft box: 2,896 mm against 2,591 mm. Almost all of that foot reaches the cargo. The inside height grows by 306 mm and the door opening by 305 mm, to 2,585 mm. The door width stays at 2,340 mm, the same as the standard box.

Reefers: a door as wide as the inside

Refrigerated containers turn the pattern round. Their insulated walls make the inside narrower, and the door opening ends up the same width as the space behind it: 2,290 mm in the 20ft reefer container, against an inside width of 2,290 mm, and 2,290 mm in the 40ft high cube reefer, against 2,287 mm. The height gap is small too: 49 mm in the 20ft reefer and 8 mm in the high cube reefer. In a reefer the door is rarely what limits a load; the narrow, low interior is. How much space the insulation costs is covered in reefer vs dry containers.

Spec sheets disagree most on exactly this figure. The high cube reefer's door height runs from 2,502 mm to 2,574 mm across four sources (ONE 2,502, SeaCube 2,502, Turkon Line 2,574, DSV 2,570), a spread of 72 mm. No other door figure in the data varies as much, so for a tall load in a reefer the door of the actual unit is worth measuring.

Which unit heights pass the door

The smallest published door height is the safe figure for the tallest single unit you can drive in. Compare it with the smallest published inside height and you get a band of unit heights that would fit inside the box but not through its door.

The band is widest in the 45ft high cube: 117 mm. Units in that band have to be loaded tilted, lowered in from above or built inside. Pallets that are meant to go two high never run into this: for every container in the table, half the inside height is well below the door, so the door only matters for single tall units. The layer arithmetic is in double stacking pallets.

Open tops: the roof is the second door

Open top containers keep the rear doors, the same 2,340 mm wide as a standard box, and add a roof opening for loads that go in by crane. The opening is smaller than the floor, because the top rails and corner castings stay in place.

The roof opening is the least consistent figure across sources. For the 20ft open top it runs from 5,440 mm to 5,757 mm, a difference of 317 mm, across four sources. A piece cut to the longest figure would not clear the shortest opening, so a crane load should be planned on the lowest published value. For a side-by-side look at open tops, flat racks and platforms, see open top vs flat rack vs platform.

The widest door: pallet-wide

The 45ft pallet-wide container has the widest opening in the data at 2,416 mm, 76 mm more than the ordinary 45ft high cube. Only Turkon Line publishes it, so treat it as one maker's figure. The door is not what makes the box carry more pallets, the inside width is; that story is in 45ft high cube vs pallet-wide.

Door heights matter in the load planner too: enter a unit taller than the opening and it flags the problem.

More guides: 20ft vs 40ft vs 40ft high cube containers · Container weights: tare, payload and max gross · Reefer vs dry container: what the insulation costs · Open top vs flat rack vs platform containers · 45ft high cube vs 45ft pallet-wide container · Double stacking pallets: which containers and trailers have the height · Half and quarter pallets: how many fit, and why they beat full pallets · All guides