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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.

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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).

MeasurementMetricImperial
Internal (L × W × H)5.90 × 2.35 × 2.39 m19′4″ × 7′8″ × 7′10″
External (L × W × H)6.06 × 2.44 × 2.59 m20′0″ × 8′0″ × 8′6″
Door opening (W × H)2.34 × 2.28 m7′8″ × 7′6″
Capacity33.2 m³1,172 ft³
Max payload28,200 kg62,170 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.

MeasurementMetricImperial
Internal (L × W × H)12.03 × 2.35 × 2.39 m39′5″ × 7′8″ × 7′10″
External (L × W × H)12.19 × 2.44 × 2.59 m40′0″ × 8′0″ × 8′6″
Door opening (W × H)2.34 × 2.28 m7′8″ × 7′6″
Capacity67.7 m³2,390 ft³
Max payload26,700 kg58,860 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.

MeasurementMetricImperial
Internal (L × W × H)12.03 × 2.35 × 2.69 m39′5″ × 7′8″ × 8′10″
External (L × W × H)12.19 × 2.44 × 2.90 m40′0″ × 8′0″ × 9′6″
Door opening (W × H)2.34 × 2.58 m7′8″ × 8′5″
Capacity76.4 m³2,700 ft³
Max payload26,500 kg58,420 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).

MeasurementMetricImperial
Internal (L × W × H)13.56 × 2.35 × 2.69 m44′6″ × 7′8″ × 8′10″
External (L × W × H)13.72 × 2.44 × 2.90 m45′0″ × 8′0″ × 9′6″
Door opening (W × H)2.34 × 2.58 m7′8″ × 8′5″
Capacity86.0 m³3,037 ft³
Max payload27,700 kg61,070 lb

All supported vessels

Internal dimensions, capacity and payload for the full 50+ vessel catalog, grouped by mode.

Sea containers

VesselInternal L × W × HCapacityMax payloadBest for
20ft Standard Shipping Container5.90 m × 2.35 m × 2.39 m33.2 m³28,200 kgDense, heavy cargo
40ft Standard Shipping Container12.03 m × 2.35 m × 2.39 m67.7 m³26,680 kgGeneral full loads
40ft High Cube Shipping Container12.03 m × 2.35 m × 2.70 m76.4 m³26,500 kgLight, bulky volume
45ft High Cube Shipping Container13.56 m × 2.35 m × 2.70 m86 m³27,700 kgMax cube per box
20ft Refrigerated Container5.44 m × 2.29 m × 2.25 m28 m³27,400 kgChilled / frozen
40ft Refrigerated (High Cube)11.56 m × 2.29 m × 2.50 m66.2 m³29,000 kgTemp-controlled volume
20ft Open Top Container5.89 m × 2.35 m × 2.35 m32.6 m³28,100 kgCrane / over-height load
40ft Flat Rack11.66 m × 2.24 m bedopen deck39,000 kgOversized & machinery
53ft Intermodal Container15.90 m × 2.44 m × 2.70 m104.7 m³20,000 kgNorth-American FTL
55ft Domestic Car Container16.51 m × 2.44 m × 4.75 m191.4 m³25,000 kgHigh-volume domestic

Road trailers & trucks

VesselInternal L × W × HCapacityMax payloadBest for
Curtainsider Semi-Trailer13.60 m × 2.48 m × 2.70 m91.1 m³24,000 kgSide-load palletised
Box/Dry Van Semi-Trailer (North America, 53ft)16.15 m × 2.59 m × 2.90 m121.2 m³22,680 kgSealed general freight
Reefer Semi-Trailer (Europe)13.20 m × 2.48 m × 2.50 m81.8 m³22,000 kgCold-chain road
Flatbed Semi-Trailer (North America, 48ft)14.63 m × 2.59 m bedopen deck25,000 kgSteel, profiles, crates
Step Deck Trailer14.63 m × 2.59 m bedopen deck22,680 kgTaller open loads
32ft Container — MXL (India)9.75 m × 2.44 m × 2.44 m58 m³16,000 kgDomestic distribution
24ft Box Truck7.32 m × 2.44 m × 2.44 m43.5 m³4,990 kgUrban / last-mile

Rail wagons

VesselInternal L × W × HCapacityMax payloadBest for
Standard Rail Boxcar17.07 m × 2.87 m × 3.11 m152.4 m³65,000 kgBulk packaged freight
Rail Flatcar (60ft)18.29 m × 3.20 m bedopen deck90,000 kgContainers & machinery
Rail Gondola Car15.24 m × 2.87 m × 2.10 m91.9 m³80,000 kgLoose 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 and PAJ 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.

VesselInternal L × W × HCapacityMax payloadBest for
LD-3 (AKE) Air ULD1.53 m × 1.56 m × 1.63 m3.9 m³1,588 kgWidebody lower deck
LD-7 (PAG / P1P) Air ULD3.17 m × 2.23 m × 1.63 m11.5 m³4,626 kgLower-deck pallet loads
LD-11 (ALP) Air ULD3.12 m × 1.47 m × 1.57 m7.2 m³3,176 kgFull-width, square-sided
PMC Pallet (P6P) Air ULD3.17 m × 2.44 m × 2.44 m18.9 m³6,804 kgMain-deck freighter build-up
PAJ Igloo Pallet Air ULD3.17 m × 2.23 m × 1.63 m11.5 m³4,626 kgDomed-shell pallet position

Dimensions by vessel

Full internal size, capacity and payload in metric and imperial, one page per vessel.

Sea containers

Trucks & trailers

Rail wagons

Air cargo ULDs

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 (PAG / P1P), LD-11 (ALP), the PMC main-deck pallet (P6P) and the PAJ igloo pallet. 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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