Twenty-foot equivalent unit
The twenty-foot equivalent unit (abbreviated TEU or teu) is an inexact unit of cargo capacity, often used for container ships and container ports. It is based on the volume of a 20-foot-long (6.1 m) intermodal container, a standard-sized metal box which can be easily transferred between different modes of transportation, such as ships, trains, and trucks.
The container is defined by its length, although the height is not standardized and ranges between 4 feet 3 inches (1.30 m) and 9 feet 6 inches (2.90 m), with the most common height being 8 feet 6 inches (2.59 m). It is common to designate a 45-foot (13.7 m) container as 2 TEU, rather than 2.25 TEU.