Container, trailer, rail & air ULD dimensions
Internal & external size, door opening, capacity and maximum payload for every vessel ContainerMath can load — 50+ sea containers, road trailers, rail wagons and air-cargo ULDs, in both feet and metres.
Key container sizes — feet & metres
The four most-used shipping containers, with internal, external and door dimensions in both units.
20ft container dimensions
A 20ft shipping container is 5.90 m (19′4″) long, 2.35 m (7′8″) wide and 2.39 m (7′10″) high inside — about 33.2 m³ (1,172 ft³) of usable space, with a payload up to ~28,200 kg (62,170 lb).
| Measurement | Metric | Imperial |
|---|---|---|
| Internal (L × W × H) | 5.90 × 2.35 × 2.39 m | 19′4″ × 7′8″ × 7′10″ |
| External (L × W × H) | 6.06 × 2.44 × 2.59 m | 20′0″ × 8′0″ × 8′6″ |
| Door opening (W × H) | 2.34 × 2.28 m | 7′8″ × 7′6″ |
| Capacity | 33.2 m³ | 1,172 ft³ |
| Max payload | 28,200 kg | 62,170 lb |
40ft container dimensions
A 40ft shipping container is 12.03 m (39′5″) long, 2.35 m (7′8″) wide and 2.39 m (7′10″) high inside — about 67.7 m³ (2,390 ft³), with a payload up to ~26,700 kg (58,860 lb). Same width and height as a 20ft, double the length.
| Measurement | Metric | Imperial |
|---|---|---|
| Internal (L × W × H) | 12.03 × 2.35 × 2.39 m | 39′5″ × 7′8″ × 7′10″ |
| External (L × W × H) | 12.19 × 2.44 × 2.59 m | 40′0″ × 8′0″ × 8′6″ |
| Door opening (W × H) | 2.34 × 2.28 m | 7′8″ × 7′6″ |
| Capacity | 67.7 m³ | 2,390 ft³ |
| Max payload | 26,700 kg | 58,860 lb |
40ft High-Cube dimensions
A 40ft High-Cube is identical to a 40ft standard but 30 cm taller — 12.03 × 2.35 × 2.69 m (39′5″ × 7′8″ × 8′10″) inside, about 76.4 m³ (2,700 ft³). The extra height suits light, bulky cargo.
| Measurement | Metric | Imperial |
|---|---|---|
| Internal (L × W × H) | 12.03 × 2.35 × 2.69 m | 39′5″ × 7′8″ × 8′10″ |
| External (L × W × H) | 12.19 × 2.44 × 2.90 m | 40′0″ × 8′0″ × 9′6″ |
| Door opening (W × H) | 2.34 × 2.58 m | 7′8″ × 8′5″ |
| Capacity | 76.4 m³ | 2,700 ft³ |
| Max payload | 26,500 kg | 58,420 lb |
45ft High-Cube dimensions
A 45ft High-Cube is the longest standard box — 13.56 m (44′6″) long, 2.35 m (7′8″) wide and 2.69 m (8′10″) high inside, about 86.0 m³ (3,037 ft³), with a payload up to ~27,700 kg (61,070 lb).
| Measurement | Metric | Imperial |
|---|---|---|
| Internal (L × W × H) | 13.56 × 2.35 × 2.69 m | 44′6″ × 7′8″ × 8′10″ |
| External (L × W × H) | 13.72 × 2.44 × 2.90 m | 45′0″ × 8′0″ × 9′6″ |
| Door opening (W × H) | 2.34 × 2.58 m | 7′8″ × 8′5″ |
| Capacity | 86.0 m³ | 3,037 ft³ |
| Max payload | 27,700 kg | 61,070 lb |
All supported vessels
Internal dimensions, capacity and payload for the full 50+ vessel catalog, grouped by mode.
Sea containers
| Vessel | Internal L × W × H | Capacity | Max payload | Best for |
|---|---|---|---|---|
| 20 ft Standard | 5.90 × 2.35 × 2.39 m | 33.2 m³ | 28,200 kg | Dense, heavy cargo |
| 40 ft Standard | 12.03 × 2.35 × 2.39 m | 67.7 m³ | 26,700 kg | General full loads |
| 40 ft High-Cube | 12.03 × 2.35 × 2.69 m | 76.4 m³ | 26,500 kg | Light, bulky volume |
| 45 ft High-Cube | 13.56 × 2.35 × 2.69 m | 86.0 m³ | 27,700 kg | Max cube per box |
| 20 ft Reefer | 5.44 × 2.29 × 2.27 m | 28.3 m³ | 27,400 kg | Chilled / frozen |
| 40 ft Reefer | 11.56 × 2.29 × 2.50 m | 59.3 m³ | 29,000 kg | Temp-controlled volume |
| 20 ft Open-Top | 5.90 × 2.35 × 2.35 m | 32.0 m³ | 28,100 kg | Crane / over-height load |
| 40 ft Flat-Rack | 12.06 × 2.40 m bed | open deck | 40,000 kg | Oversized & machinery |
Road trailers & trucks
| Vessel | Internal L × W × H | Capacity | Max payload | Best for |
|---|---|---|---|---|
| Curtainsider | 13.62 × 2.48 × 2.70 m | ~90 m³ | 24,000 kg | Side-load palletised |
| Box Trailer (Dry Van) | 13.40 × 2.45 × 2.60 m | ~86 m³ | 24,500 kg | Sealed general freight |
| Reefer Trailer | 13.30 × 2.45 × 2.50 m | ~75 m³ | 23,000 kg | Cold-chain road |
| 53 ft Dry Van | 16.15 × 2.50 × 2.80 m | ~114 m³ | 20,000 kg | North-American FTL |
| Flatbed | 13.60 × 2.50 m bed | open deck | 27,000 kg | Steel, profiles, crates |
| Step-Deck | 12.50 × 2.50 m bed | open deck | 23,000 kg | Taller open loads |
| 32 ft Domestic | 9.75 × 2.35 × 2.39 m | ~38 m³ | 16,000 kg | Domestic distribution |
| 55 ft Double-Deck | 16.15 × 2.40 × 2.60 m | ~76 m³ | 21,000 kg | High-volume domestic |
| Box Truck (Rigid) | 7.20 × 2.40 × 2.40 m | ~40 m³ | 10,000 kg | Urban / last-mile |
Rail wagons
| Vessel | Internal L × W × H | Capacity | Max payload | Best for |
|---|---|---|---|---|
| Rail Boxcar | 15.50 × 2.80 × 3.00 m | ~120 m³ | 70,000 kg | Bulk packaged freight |
| Rail Flatcar | 18.30 × 2.90 m deck | open deck | 70,000 kg | Containers & machinery |
| Gondola | 13.10 × 2.90 × 1.80 m | open top | 90,000 kg | Loose bulk / scrap |
Air cargo ULDs
IATA Unit Load Devices. Unlike the tables above, the weight column is the maximum gross weight (tare included) — the figure carriers quote — and capacity is the IATA rated volume. ContainerMath models the contoured shell of the LD-3, LD-7, LD-11 and PGF conservatively, so a plan will fill slightly less than the rated volume rather than promising space the fuselage curve doesn't leave you. Air planning is available on Pro Plus and Custom plans.
| Vessel | Internal L × W × H | Capacity | Max payload | Best for |
|---|---|---|---|---|
| LD-3 (AKE) | 1.53 × 1.56 × 1.63 m | 4.3 m³ | 1,588 kg | Widebody lower deck |
| LD-7 (AKH) | 3.18 × 2.24 × 1.63 m | 10.7 m³ | 4,626 kg | Lower-deck pallet loads |
| LD-11 (AKJ) | 3.18 × 1.56 × 1.63 m | 7.2 m³ | 3,176 kg | Long, narrow lower-deck |
| PMC Pallet (P1P) | 3.18 × 2.44 × 2.44 m | 11.5 m³ | 6,804 kg | Main-deck freighter build-up |
| PGF Igloo | 3.18 × 2.24 × 1.63 m | ~10 m³ | 6,804 kg | Domed-shell main deck |
Internal vs external — and how to use these
The figures above are internal dimensions — the usable space you load to. External (ISO) dimensions are larger, and the door opening is smaller still, so always check the door for tall or wide cargo. Capacity is the rated volume; you'll realistically fill ~80% once you account for packing gaps and weight limits.
Going deeper? Read the shipping container dimensions guide, or work out how many pallets fit in a 40ft container and how many boxes fit in a container. To plan a real load across these vessels, use ContainerMath's container loading software.
Frequently asked questions
What are the internal dimensions of a 20ft and 40ft container?
A 20ft standard container is about 5.90 × 2.35 × 2.39 m (~33.2 m³); a 40ft standard is 12.03 × 2.35 × 2.39 m (~67.7 m³) — same width and height, double the length. A 40ft High-Cube adds 30 cm of height (2.69 m, ~76.4 m³).
Are these internal or external dimensions?
Internal (usable) dimensions — what you actually load to. External dimensions are fixed by the ISO standard (a 20ft is 6.06 m long, a 40ft 12.19 m, both 2.44 m wide) and are larger than the internal figures shown here.
What's the maximum payload of a shipping container?
Most dry containers share a 30,480 kg maximum gross weight, leaving roughly 26,500–28,200 kg of payload after the container's own tare weight. Dense cargo usually hits this weight limit before it fills the volume.
What are the dimensions of a 40ft container in feet?
Internal: 39′5″ × 7′8″ × 7′10″ (12.03 × 2.35 × 2.39 m). External: 40′ × 8′ × 8′6″. A 40ft High-Cube is the same footprint but 8′10″ (2.69 m) tall inside.
How tall is a shipping container?
A standard container is 2.39 m (7′10″) tall inside; a High-Cube is 2.69 m (8′10″). Externally that's 2.59 m (8′6″) and 2.90 m (9′6″) respectively.
Is there a 20ft High-Cube container?
Yes, but it's uncommon — most 20ft containers are standard height (2.39 m / 7′10″ inside). A 20ft High-Cube keeps the same footprint with the taller High-Cube height: about 5.90 × 2.35 × 2.69 m (19′4″ × 7′8″ × 8′10″) inside, roughly 37 m³ (1,300 ft³). It's usually special-order on most lanes, so check availability before you plan around it.
How wide is a shipping container?
Every standard ISO container is 2.35 m (7′8″) wide inside and 2.44 m (8′0″) outside — from a 20ft up to a 45ft High-Cube. Internal width is the same across the range.
What are the dimensions of an LD-3 air cargo container?
An LD-3 (IATA code AKE) has a 1.53 × 1.56 m base and stands 1.63 m (64″) tall, giving about 4.3 m³ of rated volume at a 1,588 kg maximum gross weight. Its shell is contoured to follow the fuselage, so the usable space near the roofline is less than the bounding box suggests — ContainerMath accounts for that when it plans a load.
Which air cargo ULDs does ContainerMath support?
Five IATA Unit Load Devices: the LD-3 (AKE), LD-7 (AKH), LD-11 (AKJ), the PMC main-deck pallet and the PGF igloo. Contoured units are packed against an approximated shell rather than a plain rectangular box, so the plan never places cargo where the aircraft curve doesn't leave room. Air planning is on the Pro Plus and Custom plans.
What's the difference between a ULD's gross weight and its payload?
ULDs are quoted by maximum gross weight — the loaded unit including its own tare. An LD-3 rated at 1,588 kg gross carries roughly 1,505 kg of cargo once you subtract its ~82 kg tare. Sea and road equipment is normally quoted the other way round, as net payload, which is how the tables above list it.
How many vessel types does ContainerMath support?
50+ across sea, road, rail and air — including 20ft, 40ft, High-Cube, reefer, open-top and flat-rack containers, curtainsiders, dry vans, flatbeds, rail wagons and IATA air ULDs. You can also define custom vessels with your own measurements.
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