Shipping container dimensions: every type explained (2026)
Last updated: 1 July 2026
Every shipping container conversation eventually comes down to one question: will it fit? Getting that answer right starts with knowing the exact internal dimensions of the container you’re working with — not the marketing-rounded figures, but the real, usable cargo space inside the walls. A standard 20ft container measures 589 × 235 × 239 cm inside, and that internal figure — not the external 6.06 m length — is the number that decides what fits.
This guide covers internal and external dimensions for every standard container type: 20ft, 40ft, 40ft High Cube, 45ft High Cube, reefer, open top, and flat rack. All figures are verified against ISO 668 container standards. Where manufacturers vary slightly, we note the typical range rather than presenting false precision.
Why internal dimensions matter more than external ones
Internal dimensions are the only number that actually matters for load planning. External dimensions matter for stacking on a vessel, securing a container to a chassis, and calculating how many containers fit on a ship — but they tell you nothing about how much cargo you can fit inside.
The difference between internal and external dimensions comes from wall thickness, corrugation, and structural framing. A 20ft container’s external length is exactly 6.06 meters, but the internal length is approximately 5.89 meters — a 17cm difference that adds up fast when you’re planning a tight load. Always use internal dimensions when calculating space utilisation or planning cargo placement. Our free container loading calculator uses verified internal dimensions for every container type below.
Standard container dimensions
| Container type | Internal L | Internal W | Internal H | Volume | Max payload |
|---|---|---|---|---|---|
| 20ft Standard | 589 cm | 235 cm | 239 cm | 33.1 m³ | 28,080 kg |
| 40ft Standard | 1,203 cm | 235 cm | 239 cm | 67.6 m³ | 26,580 kg |
| 40ft High Cube | 1,203 cm | 235 cm | 269 cm | 76.0 m³ | 26,300 kg |
| 45ft High Cube | 1,355 cm | 235 cm | 269 cm | 86.0 m³ | 27,600 kg |
Source: ISO 668 and IICL (Institute of International Container Lessors) specifications. Figures rounded to the nearest centimetre and represent typical values — exact dimensions vary by a few centimetres between container manufacturers.
Reefer, open top, and flat rack dimensions
Specialised containers sacrifice internal space for function. A reefer container’s insulated walls and refrigeration unit reduce internal volume compared to a standard dry container of the same external size. An open top container removes the roof for top-loading oversized cargo. A flat rack removes both the roof and side walls entirely, leaving only a base and end walls for cargo that needs to be loaded and secured from the side.
| Container type | Internal L | Internal W | Internal H | Max payload | Notes |
|---|---|---|---|---|---|
| 20ft Reefer | 543 cm | 228 cm | 226 cm | 27,400 kg | Insulated walls reduce internal space |
| 20ft Open Top | 589 cm | 235 cm | 232 cm | 28,180 kg | Removable tarpaulin roof |
| 20ft Flat Rack | 589 cm | 244 cm | N/A | 27,500 kg | No roof or side walls — open platform with end walls |
Flat rack containers have no enclosed height limit in the traditional sense — cargo height is limited only by vessel stowage and transport clearance rules, not by container walls.
External vs internal dimensions — quick comparison
For reference, here is how external and internal dimensions compare for the two most common container types.
| External L × W × H | Internal L × W × H | |
|---|---|---|
| 20ft Standard | 606 × 244 × 259 cm | 589 × 235 × 239 cm |
| 40ft Standard | 1,219 × 244 × 259 cm | 1,203 × 235 × 239 cm |
How to use these dimensions in a load plan
Knowing the dimensions is the first step — using them accurately is where most manual planning goes wrong. The most common mistake is using external dimensions to estimate how much cargo fits, which overstates available space by several centimetres in every direction. Over a full container load, that error compounds into genuinely wrong capacity estimates.
For a quick volume check, our free CBM calculator uses these exact internal dimensions to tell you how much cargo fits by volume alone. For an accurate 3D placement that accounts for stacking, item shape, and weight distribution — not just raw volume — use the container loading calculator, which generates a full load plan in under 50ms.
Frequently asked questions
What are the dimensions of a shipping container?
A standard 20ft shipping container has internal dimensions of 589 × 235 × 239 cm and an internal volume of approximately 33.1 cubic meters. A standard 40ft container has internal dimensions of 1203 × 235 × 239 cm with a volume of approximately 67.6 cubic meters. Exact figures vary slightly by manufacturer within ISO 668 tolerances.
What is the difference between a 20ft and 40ft container?
A 40ft container is almost exactly double the length of a 20ft container and has roughly double the internal volume — 67.6 m³ versus 33.1 m³. The 40ft container has a slightly lower maximum payload (26,580 kg) than the 20ft (28,080 kg) because the longer steel structure itself weighs more, leaving less allowance within the same gross weight limit.
What is a high cube container?
A high cube container is 30cm taller than a standard container of the same length. A 40ft High Cube has an internal height of 269cm versus 239cm on a standard 40ft, giving roughly 12% more volume — about 76 m³ versus 67.6 m³. High cube containers are commonly used for lightweight but bulky cargo such as furniture, textiles, or empty packaging.
What is a reefer container and how is it different in size?
A reefer (refrigerated) container has thicker insulated walls than a standard dry container, which reduces internal space. A 20ft reefer has internal dimensions of approximately 543 × 228 × 226 cm — smaller than a standard 20ft container’s 589 × 235 × 239 cm — because the insulation and refrigeration unit take up part of the internal volume.
How much weight can a shipping container hold?
A standard 20ft container has a maximum payload of approximately 28,080 kg. A standard 40ft container holds approximately 26,580 kg. A 40ft High Cube holds approximately 26,300 kg. These figures exclude the container’s own tare weight and represent the cargo weight limit only — always confirm exact limits with your carrier as they can vary by a few hundred kilograms between manufacturers.
What is the difference between internal and external container dimensions?
External dimensions describe the container’s footprint for stacking, securing, and vessel slot allocation — for example a 20ft container’s external length is exactly 6.06 meters. Internal dimensions describe the usable cargo space inside the walls, which is always smaller due to wall thickness, corrugation, and structural framing — a 20ft container’s internal length is approximately 5.89 meters, about 17cm less than the external length.
What is a flat rack container?
A flat rack container has no roof and no side walls — only a base and two end walls — designed for oversized or irregularly shaped cargo like machinery, vehicles, or pipes that cannot fit through a standard container door. A 20ft flat rack has a usable length of approximately 589cm and a usable width of approximately 244cm, with cargo secured using lashing points rather than enclosed walls.
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