TEU

From UG

TEU - The twenty-foot equivalent unit (often TEU or teu) is an inexact unit of cargo capacity often used to describe the capacity of container ships and container terminals. It is based on the volume of a 20-foot long intermodal container, a standard-sized metal box which can be easily transferred between different modes of transportation, such as ships, trains and trucks.[1]

TEU capacities for common container sizes:

20 ft ~ 1 TEU
40 ft ~ 2 TEU 
45 ft ~ 2 or 2.25 TEU 
48 ft ~ 2.4 TEU 
53 ft ~ 2.65 TEU

It is common to designate 45-foot (14 m) containers as 2 TEU, rather than 2.25 TEU.