There are limitations when shipping your cargo in a container. The limitations include size, weight and contents. The internal dimensions of a 20ft container are approximately 19.5ft long by 7.5ft high and 7.5ft wide. The weight limit for a 20ft container is approximately 20,000 pounds. The internal dimensions of a 40ft container are approximately 39.5ft long by 7.5ft high and 7.5ft wide. The weight limit for a 40ft container is approximately 40,000 pounds. You may not ship any combustible materials and you are limited by what the destination country will allow you to import.