Twenty-Foot Equivalent Unit (TEU)

The TEU is the container-trade capacity unit equal to one 20-foot ISO container: nominally 20 ft long, 8 ft wide, 8 ft 6 in high (6.058 by 2.438 by 2.591 m). A standard 40-foot box counts as two TEU; a 40-foot high-cube also counts as two TEU despite the extra height. TEU measures slot capacity, not weight, so a ship’s TEU rating and its deadweight limit are independent constraints; a fully slotted box ship often cannot fill every slot with heavy cargo without exceeding deadweight.