What is Twenty-foot Equivalent Unit?
The twenty-foot equivalent unit (TEU) is the standard unit for measuring container capacity and volume, equal to one 20-foot ISO container. A standard 40-foot container counts as two TEU, and a 40-foot high cube is also generally counted as two TEU even though it is taller; some statistics use the forty-foot equivalent unit (FEU) instead. The dimensions behind the unit come from ISO 668, which classifies series 1 freight containers by external dimensions and sets their ratings; the 20-foot container (type 1C) has an external length of 6,058 mm and a width of 2,438 mm. TEU measures ship size, terminal capacity and port throughput, but says nothing about cargo weight. Port throughput figures count containers loaded and discharged, including empty and transshipped boxes.
Why it matters for forwarders
Forwarders use TEU to compare carrier capacity, report volumes to customers and negotiate service contracts, which often state minimum quantity commitments in TEU or FEU. Rates are quoted per container type, though, so a 40-foot rate is rarely exactly twice a 20-foot rate and conversions should be explicit in reports and tenders. Heavy cargo often fills a 20-foot container by weight before it is full by volume, so a TEU count alone does not show how much freight a customer ships. When reporting KPIs, state whether TEU figures include empties, transshipment and reefers, as mixed definitions make comparisons unreliable. Vessel capacity in TEU is a nominal figure, and the number of loaded containers a ship can actually carry is lower when cargo is heavy.