There are limitations when shipping your cargo in a container. These limitations include size, weight and content. The internal dimensions of a 20ft container are approximately 5.9-metre long x 2.35-metre wide x 2.39-metre high. The difference for a 40ft container would be the length, which can accommodate up to 12 meters. The weight limit of a 20ft container is approx. 25 tons whilst a 40ft container can withstand up to 27 tons.