TEU

TEU — Twenty-foot Equivalent Unit — is the standard unit of measure for container volumes in maritime shipping. One TEU equals one 20-foot ISO container (approximately 33 cubic meters of internal capacity, 28,000 kg maximum gross weight). A 40-foot container counts as two TEU, and a 45-foot high-cube counts as approximately 2.25 TEU.

TEU is the universal metric for:

• Vessel capacity — Modern Ultra Large Container Ships (ULCS) like the MSC Irina carry 24,000+ TEU. Panamax vessels max out around 5,000 TEU; New Panamax around 14,000 TEU.
• Port throughput — Shanghai, the world's largest container port, handles over 47 million TEU annually. The Port of Los Angeles handles roughly 9 million TEU; Long Beach about 9.5 million.
• Carrier capacity rankings — Liner shipping companies are ranked by total fleet TEU. MSC, Maersk, and CMA CGM operate the largest fleets.

The TEU concept dates to the rapid containerization of the 1960s and 1970s, when 20-foot units were the original ISO standard. The industry has shifted heavily toward 40-foot equipment (better economics per cubic meter) — most ocean trade today actually moves in 40' boxes, but capacity is still reported in 20-foot equivalents for backward comparability.

For a single shipper booking, "TEU" almost never appears on the bill of lading — that's "1x20' DC" or "1x40' HC." TEU is a fleet-level and port-level accounting unit.