TEU — the twenty-foot equivalent unit — is the unit the container world runs on. Ships are sized in TEU, ports report throughput in TEU, trade statistics and carrier market shares are compared in TEU. The unit itself is trivially simple: one standard 20-foot container equals one TEU. The useful part is knowing what the unit does and does not measure — because TEU counts slots, not cargo, and the gap between the two is where planning mistakes live. This guide covers the definition, the conversion table, the places TEU shows up, and how to translate TEU into actual cubic meters of freight.
The definition, and the conversion table
A TEU is the footprint of one ISO 668 standard 20-foot container: 20 ft (6.06 m) long and 8 ft (2.44 m) wide. Capacity expressed in TEU is a length count — how many 20-foot slot lengths something occupies or provides. The height of the box is ignored entirely.
| Container | Length | TEU | Also called |
|---|---|---|---|
| 20ft (GP / standard) | 6.06 m | 1 | — |
| 40ft (GP / standard) | 12.19 m | 2 | 1 FEU |
| 40ft high cube | 12.19 m | 2 | 1 FEU — height does not change the count |
| 45ft high cube | 13.72 m | 2.25 (often counted as 2) | — |
| 53ft (North American domestic) | 16.15 m | ≈2.65 — not an ISO deep-sea size | — |
The 45-footer is the one genuine ambiguity: dimensionally it is 2.25 TEU, but slot planning and much commercial practice round it to 2 because it rides a 40-foot cell with an overhang. If a statistic matters to you, check which convention it uses.
What TEU measures — and what it does not
TEU is a count of slot lengths. Three consequences follow, and each one trips someone up regularly:
It ignores height. A 40ft high cube carries about 13% more volume than a standard 40ft, yet both are 2 TEU. Two fleets with identical TEU counts can differ meaningfully in actual cubic capacity depending on their high-cube share.
It ignores weight. A vessel's TEU rating assumes an average container weight (commonly around 14 tonnes per TEU in homogeneous-load terms). Load heavier boxes and the ship reaches its deadweight or stability limits with slots still empty — which is why a "24,000 TEU" vessel practically never sails with 24,000 loaded TEU aboard.
It says nothing about the cargo inside. A TEU of ping-pong balls and a TEU of steel coil are the same TEU. For cargo planning you need cubic meters and kilograms, not equivalent units — the conversion is the last section of this guide.
Where TEU shows up
Vessel capacity. Ship classes are named and compared by TEU rating: feeders run roughly 300–3,000 TEU, Panamax-era designs around 4,000–5,000 TEU, and today's largest ultra-large vessels are rated just over 24,000 TEU.
Port and trade statistics. Port league tables are TEU throughput per year — the world's busiest container port handles on the order of 50 million TEU annually. Note that throughput counts lifts of loaded and empty boxes, and a transshipped container is counted each time it crosses the quay, so throughput is not the same thing as trade volume.
Rates and indices. Here the sibling unit takes over: major spot-rate indices quote per FEU, because the 40-foot box dominates deep-sea trades. Your own quote, however, is per container of a specific type — nobody bills you "per TEU" for a single shipment.
From TEU to actual cargo
To turn a TEU figure into freight, use the volumes of the underlying boxes, not the unit. One 20-foot container offers about 33 m³ nominal internal volume and roughly 28 t of payload; one FEU offers about 67.7 m³ (76.3 m³ as a high cube) with a similar payload ceiling. Real-world stow of mixed cartons reaches about 80–85% of nominal volume, so plan on roughly 25–28 m³ per TEU — the CBM-per-container guide breaks down why. Exact internal dimensions, door apertures, and tare weights for every common type are in the container dimensions guide, and for a concrete shipment you can skip the averages entirely: the container loading calculator stows your actual carton list in 3D and tells you whether it fits in the 1 TEU box or needs the FEU.
What does TEU stand for?
TEU stands for twenty-foot equivalent unit. It is the standard unit of container shipping capacity, equal to one 20-foot ISO container. Ship sizes, port throughput, and trade volumes are all quoted in TEU.
Is a 40ft container 1 TEU or 2 TEU?
A 40-foot container counts as 2 TEU, because it occupies two 20-foot slot lengths. It is also called 1 FEU (forty-foot equivalent unit). The count is based on length only, so a 40ft high cube is still 2 TEU despite the extra height.
What is an FEU?
FEU is the forty-foot equivalent unit: one 40-foot container, equal to 2 TEU. Ocean freight rate indices such as the major Asia–Europe and transpacific spot indices are typically quoted per FEU, because the 40-foot box dominates deep-sea trades.
How many TEU is a 45ft container?
Geometrically a 45-foot container is 2.25 TEU, and statistics that track exact dimensions use that figure. In slot planning and many commercial contexts it is treated as 2 TEU, since it occupies a 40-foot slot with an overhang allowance.
How much cargo actually fits in 1 TEU?
A 20-foot container has about 33 m³ of nominal internal volume and a payload around 28 tonnes, but real cartons stow to roughly 25–28 m³ because of box geometry and stacking limits. That practical factor matters more than the nominal figure when converting TEU counts into cargo.
How big are the largest container ships in TEU?
The largest ultra-large container vessels in service are rated at just over 24,000 TEU. A rating like that is a slot count at maximum stow, not a promise — the sailing draft and the weight of the actual cargo mix usually cap effective capacity below the nominal number.