it turns out not all containers are exactly the same size.
A 20’ container it turns out isn’t a 20’ container.
Also, it’s interesting that if you search for “Shipping container dimensions or Shipping container sizes” you don’t get a straight answer. The reason for that is that the ISO standard for container sets the external dimensions, but only a MINIMUM for internal dimensions. IF you look at the chart below you can see these two things.
- A 20’ container is about an inch and a half short of 20’. Why is that? To allow for stacking of 20’ and 40’ containers with a small space in between the 20’ containers.
- Different manufacturers use different materials for constructing their containers, so some containers will have larger internal dimensions than others, but using the chart below you can be assured of the minimum dimensions for a container. That is for a 20’ container: 19’3” X 7’7 ¾” X 7’8 ½”. (Most containers are 8’6” high)
40’ containers however are 40’ in length and have the same height and width dimension as 20’ containers.
The external dimensions of containers are specified in ISO 668, with the maximum dimensional tolerances being ± 10 mm. The internal dimensions are minimums. Internal container dimensions vary from manufacturer to manufacturer, but they must satisfy the minimum criterion below.