Understanding shipping container dimensions is a crucial part of a successful build. The multitude of shapes and sizes of shipping containers (Open-top, high-cube, 48-footer, flat-rack, etc.) leads to numerous configurations that you can purchase.
While the standard 40-foot shipping container is what most people are familiar with, there are longer, shorter, wider, and taller options available. In order to properly design a shipping container house, you need to really understand the empty shipping containers that serve as the building blocks for your project.
In order to help you find what you’re looking for faster we’ve divided this article into the following sections:
The ISO Standards governing shipping container sizes give manufacturers some leeway with regard to required dimensions. This is typically done by specifying the minimum or maximum values for a particular dimension.
What this effectively means is that there can be some small variability in the dimensions of containers that are the same size and type. This is true when comparing between manufacturers but also even in different product lines from the same manufacturer. In most cases, the differences are no larger than ½ inch or so, which is pretty small given the large size of a container.
However, reefer or refrigerated containers have more variability in their dimensions as they are not all designed for the same temperature requirements and thus have different amounts of insulation.
In general, exterior dimensions are less variable as ultimately all containers need to be able to attach together. Things like door height or interior length may have a bit more variability.
Another area of variability is in the weights. For instance, some container manufacturers choose to exceed the minimum required strength, and in doing so their containers may weigh more to account for additional materials.
With that in mind, you may come across containers with differences in gross, tare, or payload weights that differ by hundreds or even thousands of pounds. As we discussed above, the ISO requires minimums for the strength, but manufacturers can exceed it.
Finally, as you’ll see below, there are MANY possible container configurations. We can’t cover every option, and even if we could, we can’t provide every dimension for each one.
Instead, we’ll focus on the most commonly requested dimensions from the most commonly used containers. And, we’ll to always provide both US units and metric shipping container dimensions for our readers around the world.
You may have come across some uncommon technical terms as you get to know more about shipping containers. Below are the definitions for a few container-related words that you’ll need to be familiar with:
There are also a few quick things to understand about dimensions as well:
Containers are identified by a 4-digit alphanumeric size and type code specified in ISO 6346. The first two digits are what is called the ‘size code’ and the second two digits are the ‘type code’:
Let’s try a few examples:
You can look up the meaning of most of these codes with this tool.
As we mentioned previously, there can be slight differences in the measurements of containers from different manufacturers. While it’s sometimes hard to find the information about specific manufacturers, you may be able to find the shipping line or company that originally used the container and get relevant information that way.
Now we’re ready to get into actual dimensions. We start off with common container varieties. These are the containers you’re most likely to see out ‘in the wild’ and for sale. After this section, we’ll cover other containers that are a bit less common.
The standard 20ft shipping container is popular due to its ease of maneuverability and lower weight. There are some people that make tiny cabins out of a single 20ft container, but more often than not, they are used as part of a larger build.
While 20ft containers are cheaper than their corresponding 40ft alternatives, their price per square foot is actually more expensive. So unless your design actually requires 20ft containers, using 40ft ones is usually a better way to get more floor space.
The 20ft high cube container is similar to a standard 20ft container but with the added room of an additional 12 inches of height. This makes it easier to have interior insulation and light fixtures while still maintaining a normal ceiling height.
The 20ft refrigerated shipping container is a regular 20ft container with the added benefit of insulation. If you’re planning to insulate anyway, this could be a shortcut depending on some of your other design choices. We’ve written an article on the things to think about with refrigerated containers to help you.
A 40ft shipping container is the most common container you will find. They are big enough to allow splitting them up into multiple rooms (for example, a one-bedroom home) but they can also be combined into a home of any size. Like the general purpose 20 foot containers, their lower ceiling height could be an issue for those that want interior insulation while still having a reasonable ceiling height.
If you like the size of a 40ft container but need a bit more vertical space, a 40ft high cube container offers you the same floor area with the additional one foot of overhead room. This gives you the extra volume for insulation, wiring, and fixtures while still being able to have an 8ft interior ceiling height.
With a 40ft refrigerated or reefer container, you get the benefits of a 40ft container along with built-in insulation. However, in most cases, this also includes an industrial refrigeration unit that you’ll want to get rid of, and you’ll have to patch over the hole it leaves. For this reason and others, you should learn more about the pros and cons of building with refrigerated containers.
If you love the size of a 40ft container and the included insulation of a refrigerated container, but you want a bit more head room, a 40ft refrigerated high cube container might be the right choice. It won’t offer you the ability to easily embed your wires behind the ceiling like you could with a regular container where you add insulation later. But if you like an industrial look with surface mounted conduit and high loft-esque ceilings it could be a great fit.
The 45-foot containers are a bit different than what we’ve previously discussed. They have the normal container corner castings 40 ft apart, but then they have two equal ~2.5ft extensions on each end of the container. These extensions also have corner castings at the actual corner extents of the container. Having multiple sets of corner castings allows 45ft containers to be stacked with 40ft containers.
Most 45ft containers you see are high-cubes with the additional benefits that an extra foot of room height brings. Thanks to their added five feet of length, 45-foot containers allow you to have a container home with slightly bigger rooms. It’s even possible to make a two-bedroom unit if you can be space-efficient.
The containers in this group are certainly less common than those above but are still fairly widely available in certain regions as we explain below.
A 48ft container is the first container we’ll discuss that has a different width than all containers previously mentioned. With an additional 6in of width, a 48ft container is 6.25% wider than a 40ft or 45ft container. It doesn’t sound like much, but this extra width gives you just a bit more breathing room for insulation while not feeling like your rooms are too narrow. Most 48ft containers are also high cubes, so they have an extra 12in of height as well.
Much like a 45ft container, a 48ft shipping container has multiple sets of container corner castings: one set at the actual corners, and one set 40ft apart. This enables it to be stacked with 40ft containers. The two ~4ft extensions on each of the 48ft containers are similar in design to those of the 45ft container, just a bit longer.
With an additional 8ft of length and 6in of width, a 48ft container makes having a second bedroom or just bigger other rooms possible. The ~4ft extensions on each end are also possible candidates for cantilevered areas on the upper floors.
The 53ft container is largest mass-produced container that you’re likely to ever see. Like a 48ft container, it is also 6in wide than a 40ft container. And like a 48ft container, a 53ft container has corner castings at 40ft, followed by two equal extensions that bring the length out to 53ft. However, the extensions on a 53ft container are about 6.5ft long each. Basically all 53ft containers are high cube which grants you an extra foot of interior clearance.
If you want to build something using only a single container, a 53ft container gives you the larger possible volume. However, depending on where you’re located, it may be cheaper to buy multiple, small containers instead of one large 53ft container. More importantly, 53ft containers have limited availability and are mostly just used in North America.
Initially, 53-foot containers weren’t built strong enough for ocean travel, as they were only intended for domestic shipments in the United States. However, some companies eventually created reinforced 53-footers that were up to the task of ocean voyages. Something to keep in mind when you’re shopping if you’re thinking about structurally taxing designs like bridging.
Pallet wide containers just a bit wider (roughly 2in) than regular width containers, but not as wide as 48ft and 53ft containers. The extra width is to accommodate ‘euro pallets’.
Standard pallets in the United States and some other countries are 48in (1219mm) by 40in (1016mm). In contrast, Euro pallets are 800mm (2ft 7.5in) by 1200mm (3ft 11.2in). The slightly wider size of a pallet wide 40ft container allows it to hold 30 euro pallets, while a regular 40ft container can only hold 25.
If you aren’t planning to store pallets, this extra width just give you a tiny bit more space for your interior walls, insulation, etc. Whether it’s worth paying extra for this small bit of additional width really depends on your design. But for people, if you’re going to pay extra, you might as well go for a longer 48ft container where you also get then 6in wider width.
You’re most likely to find pallet wide containers in Europe, where euro pallets are prevalent. But they may pop up in other locations as well that trade with Europe.
The below containers are fairly rare but we’ll still acknowledge their existence in case you happen to stumble across one. This is far from a complete list of every possible shipping container though.
One of the signature parts of a container is its cast metal corners. The solid chunks of steel have elongated holes in them that are what the twist-lock fittings attach too. The corners are what give containers their modularity and allow them to be attached to other things and each other.
The corner fittings themselves are made of cast steel and typically have holes in the three sides that don’t face back towards the container itself.
In general, the holes are roughly 2-3 inches in diameter (though oblong), but they aren’t all shaped alike. There is also a difference in some of the holes depending on if the corner is at the top or bottom of the container.
To see very specific measurements of each hole on each corner container, either reference ISO 1161 or find a reseller/manufacturer who sells the fittings and has detailed shop drawings available like Tandemloc or Pacific Marine.
Part of understanding the corners themselves is understanding how they are spaced. The exterior size of a container is slightly less important than the position of the corner fittings. The corners are the places where containers touch each other, and thus their positioning is crucial.
The most important container corner dimension is the distance between the center of the holes both widthwise (labeled ‘P’ above) and lengthwise (labeled ‘S’ above).
For effectively all containers, P is 2259mm (7ft 4.94in). For 40ft containers, S is 11985mm (39ft 3.85in). For 20ft containers, S is 5853mm (19ft 2.43in)
Wider containers liked pallet wide and 48ft/53ft models, normally still have the same P measurement. This is done by having the holes in their corner fittings moved a little bit inward.
The containers we have discussed that are longer than 40 feet (45ft, 48ft, and 53ft containers) actually have an extra eight ‘corner’ fittings that are 40ft apart in addition to the fittings at the actual corners.
The extra eight ‘corner’ fittings, sometimes called intermediate corners, can be shaped a little different than normal corners. As mentioned earlier, the longer containers can be a few inches wider, and thus the intermediate corner fittings have to position the holes inboard a bit to correctly interface with regular containers.
The vertical distance between the centers of the holes in the top and bottom container corner fittings varies based on the height of the container. The distance is usually about 5.6in (142mm) less than the overall height, though it isn’t directly specified by the ISO.
Containers are famous for the corrugated sheet metal panels that make up their sides and top. While not all containers have them (for instance, refrigerated containers have smooth exteriors), most do in order to get added strength. And while there can be some variability in the dimensions of the corrugations, most modern containers do use the same corrugation dimensions.
One thing you may not know is that the actual corrugations are different between the long sides, the short side (the front and back including the doors), and the top. Below we’ll show dimensions of all three types of corrugations.
The sides of a container typically have vertical corrugations. The overall thickness of the corrugation is what contributes to the loss in the interior width of a container, which is why this corrugation, in particular, is important to pay attention to.
Most containers only have one set of doors, while the other end is a solid wall of corrugated steel. This solid end has a different corrugation that is unique. However, it is oriented vertically, so it may appear similar to the side corrugation from far away.
Every container has at least one set of doors, and the double-ended (tunnel) containers have two sets. The doors themselves have corrugations, though the number and orientation of the corrugations vary quite a bit between containers.
Typically there are two to five horizontal corrugations per door, although three is the most common and what we cover above. Usually, the horizontal corrugations are vertically centered on each door.
The roof of a shipping container has a unique shape that is a little different than the other pieces of sheet metal. Instead of just being a flat piece of steel that is bent in only one dimension (so that the entire length of the panel has the same cross-section as the back and sides), the roof is shaped in three dimensions.
First, it has a very slight camber or convex bend in it, so the water will flow to the sides of the container. Also, the corrugations don’t go all the way to the edges of the roof, but rather end in a circle a few inches from the edge.
The floor of a shipping container is typically made of plywood (thin sheets or plys of wood veneer that are glued together, with each ‘ply’ turned 90 degrees from the one below it). As mentioned previously, some containers use bamboo or metal flooring, but this isn’t as common.
The plywood in a container home is usually about 1-1/8 in (28mm) thick and made out of either 19 or 21 plies of high-density tropical hardwoods.
The plywood is screwed into steel C-channel cross members under the floor the span across the width of the container. Container manufacturers don’t have a standard size and spacing of these cross members so we won’t give any dimensional information. However, they are typically no more than spaced less than 2ft apart and are welded to both bottom rails of the container.
The area open area under the floor and between the cross members typically has about six inches of vertical free space above ground level, which is where you can run utilities. The spacing of cross members is also affected by the presence of forklift pockets and the gooseneck tunnel.
We hope you are now confident in understanding how the size of a shipping container factors into how it will work in your next project. One of the biggest points to understand is that your location has a large effect on the availability of different types and sizes on containers.
We recommend seeing how easily the less common sizes and configurations can be sourced in your area. This will keep you from spending too much time developing a design that’s not feasible because you’d have to pay exorbitant fees to have uncommon containers brought in for your project.
Once again, remember that ISO grants a bit of tolerance on the measurements they specify. And, some other measurements are up to the manufacturer. If you have something that requires knowing a dimension down to the mm level, it would be best to field measure it on the actual containers your purchase.
Have you used any unique containers that we didn’t cover in your project? Let us know in the comments below.