Shipping Container Sizes, Dimensions and Weights

Standard shipping container sizes

Shipping container sizes are standardized internationally by ISO 668, which classifies series 1 freight containers by their external dimensions and sets their ratings. Four dry container sizes carry nearly all ocean imports: the 20' standard, the 40' standard, the 40' high cube and the 45' high cube. All share the same 8 ft external width; they differ in length and height.

Internal dimensions, tare weight and payload vary slightly by manufacturer, floor type and build year. The figures on this page are nominal values from ISO 668 (external) and a major ocean carrier's published specifications (internal and weights). For an exact limit on a specific box, check the CSC plate and markings on the container doors. Unfamiliar terms are defined in our shipping glossary.

External container dimensions (ISO 668)

External dimensions are fixed by the standard so containers stack, lock and ride on chassis, railcars and ships interchangeably.

Internal container dimensions and door openings

Internal dimensions decide what fits inside. Door openings are smaller than the interior, which matters for tall machinery or pallets built close to the ceiling.

Container capacity (CBM) and weight limits

Capacity in cubic meters (CBM) tells you how much volume a container holds. Payload tells you how much cargo weight it can legally carry. Dense cargo reaches the weight limit long before the box is full.

20ft vs 40ft container: which is better?

A 40' container has a little more than twice the volume of a 20' (67.7 m³ vs. 33.2 m³) but nearly the same maximum payload. That makes the 20' the usual choice for heavy, dense cargo such as tile, stone, metal parts or bagged goods, which hit the weight limit long before filling the box. The 40' suits lighter, bulkier goods like furniture, apparel, toys and housewares.

Ocean rates for a 40' are often less than double the 20' rate, so for light cargo the 40' is cheaper per cubic meter. For heavy cargo, two 20' containers can carry more total weight than one 40', and each 20' is easier to keep within road weight limits.

High cube container size and when it helps

A high cube container is one foot taller than a standard container: 9 ft 6 in externally instead of 8 ft 6 in, with about 2,700 mm of interior height instead of about 2,395 mm. On a 40', that adds roughly 8.6 m³ of capacity (76.3 m³ vs. 67.7 m³) for nearly the same tare weight.

High cubes help light, bulky cargo and floor-loaded cartons that can be stacked an extra tier. They do not add floor space, so they do not fit more single-stacked pallets. Their extra height can also matter on the road, since a high cube on a standard chassis sits closer to height limits under bridges and in some warehouse doorways.

How many pallets fit in a container?

Pallet counts depend on pallet size and loading pattern. For standard 48 x 40 in pallets, single-stacked, the interior width of about 92.6 in fits one pallet turned each way side by side (40 in + 48 in = 88 in).

Container weight and U.S. road limits

A container's maximum gross weight is not the same as what can legally travel on U.S. highways. Federal rules for the Interstate system cap a vehicle at 80,000 lb gross, 20,000 lb on a single axle and 34,000 lb on a tandem axle group (23 CFR 658.17). The tractor, chassis and container all count toward the 80,000 lb.

Example (hypothetical weights): if a tractor and chassis together weigh 35,000 lb, the loaded container can weigh at most 45,000 lb gross to stay under 80,000 lb. Subtract the 40' container's tare of about 8,267 lb, and the cargo itself can weigh only about 36,700 lb, far below the container's rated payload of 63,383 lb.

That gap is why heavy containers often travel on triaxle chassis, which spread weight across three axles to help with axle limits, and why heavy imports are often transloaded near the port into domestic trailers at legal weights. Plan cargo weight with the road leg in mind, not just the ocean leg. Domestic trailer options are compared in FTL vs. LTL.

Specialized container types

Beyond dry containers, a few special types handle cargo that does not suit a standard box.

TEU and FEU explained

A TEU (twenty-foot equivalent unit) is the standard unit for counting container volume. A 20' container is 1 TEU, and a 40' container, whether standard or high cube, is 2 TEUs, also called one FEU (forty-foot equivalent unit). Port statistics use TEUs: the Port of Long Beach handled about 9.9 million TEUs in 2025, and the Port of Los Angeles more than 10.2 million. For how those containers move inland, see importing through Los Angeles and Long Beach.

How shipping container sizes affect drayage and unloading

• Chassis. The container must match the chassis length; heavy containers may need a triaxle chassis. See what is drayage and port drayage services.
• Unloading time. A floor-loaded 40' holds about twice the cartons of a 20' and takes roughly twice the labor to unload.
• Transloading ratio. A 53' domestic trailer has more interior space than a 40' container, so freight from about three 40' containers often fits into two 53' trailers. See transloading vs. cross-docking.
• LCL vs. FCL. When an LCL shipment approaches the volume of a 20', a full container may cost less; see what is a container freight station.
• Detention. Every container size carries per diem once it leaves the terminal; see demurrage and detention and last free day.
• Reefers need power. A loaded reefer can only be stored or pre-pulled at a yard with plug-ins, so many reefer moves go straight from the terminal to the receiver.
• How we handle these sizes. At Long Beach and Los Angeles we pull 20', 40', 40' high cube and 45' containers, reefers (delivered direct, since our yard has no reefer plug-ins), hazmat containers with the hazard class confirmed per shipment at quote time, and open-top, flat-rack and overweight containers with permits arranged when required.

Frequently asked questions