The three most common container types in ocean freight are the 20ft standard dry container, the 40ft standard or high cube dry container, and the reefer container. A 20ft container holds approximately 33 cubic meters and suits shipments of dense, heavy cargo up to around 25,000 kg. A 40ft container holds roughly 67 cubic meters and is the best choice for lighter, bulkier cargo or larger volumes. A reefer container is a refrigerated unit that maintains controlled temperatures for perishable cargo, pharmaceuticals, and temperature-sensitive goods. Choosing the right container type depends on your cargo volume, weight, dimensions, and whether it requires temperature control.

Picking the right container is one of the most practical decisions in ocean freight, and it is one that catches many importers off guard. The wrong choice adds cost, creates loading problems, or puts your cargo at risk. The right choice makes your shipment efficient, safe, and straightforward to clear through customs.

This guide covers every major container type used in commercial ocean freight, with exact specifications, ideal cargo types, and the practical factors that determine which container your shipment actually needs. The team at Express Ocean Logistics uses this knowledge on every shipment we handle, and we have condensed it here so you can make informed decisions before you book.

Why Container Selection Matters More Than Most Importers Realize

Container type affects more than just the space your cargo occupies. It determines whether your goods can be loaded safely, whether they will arrive in the same condition they left, and whether your shipment is compatible with the carrier's loading equipment and port handling procedures. An overloaded container can be rejected by the terminal or cause safety incidents at sea. A container that is too large for your cargo volume wastes money on unused space while still requiring you to pay for the full container.

For importers working with a freight forwarder, the container selection conversation happens early in the booking process. Your forwarder needs your cargo's weight, volume, dimensions, and any special handling requirements before they can advise on the right unit. If you are planning your first ocean freight shipment and want an overview of how the full process works from that initial booking through delivery, our guide on shipping by ocean freight for the first time covers every stage in order.

The 20ft Standard Dry Container

20ft Standard Dry Container
1 TEU  |  Most common unit for dense, heavy cargo
Internal Length
5.90 m / 19.4 ft
Internal Width
2.35 m / 7.7 ft
Internal Height
2.39 m / 7.8 ft
Volume (CBM)
~33 cubic meters
Max Payload
~28,200 kg
Tare Weight
~2,200 kg

The 20ft standard dry container is the foundational unit of ocean freight. It is the basis for the TEU measurement used across the entire shipping industry. It works best for cargo that is dense and heavy relative to its volume, because it reaches its weight limit before its volume limit in most loading scenarios. Machinery, steel, automotive parts, tiles, and industrial equipment are all well-suited to the 20ft container.

Best for:

Heavy machinerySteel productsAutomotive partsTiles and stoneIndustrial equipment15 to 25 CBM volumes
Weight vs volume limit: The 20ft container's payload limit of approximately 28,200 kg is reached before its 33 CBM volume limit for most categories of heavy industrial cargo. If your cargo weighs more than 20,000 kg but only fills 15 CBM, a 20ft container is almost certainly the correct choice and a 40ft container would be an unnecessary expense.

The 40ft Standard Dry Container

40ft Standard Dry Container
2 TEU  |  Most versatile all-purpose container
Internal Length
12.03 m / 39.5 ft
Internal Width
2.35 m / 7.7 ft
Internal Height
2.39 m / 7.8 ft
Volume (CBM)
~67 cubic meters
Max Payload
~26,500 kg
Tare Weight
~3,900 kg

The 40ft standard dry container offers roughly double the volume of a 20ft unit at a freight rate that is significantly less than double, which makes it the most cost-efficient choice for most commercial import volumes. Note that the 40ft container has a slightly lower maximum payload than the 20ft, because its heavier tare weight (the weight of the empty container itself) consumes more of the gross weight limit set by the shipping line and port regulations.

Best for:

Consumer goodsClothing and textilesElectronicsPlastics and packaging25 CBM and aboveMost retail imports

The 40ft High Cube Container

40ft High Cube Container
2 TEU  |  Extra height for voluminous, lightweight cargo
Internal Length
12.03 m / 39.5 ft
Internal Width
2.35 m / 7.7 ft
Internal Height
2.69 m / 8.8 ft
Volume (CBM)
~76 cubic meters
Max Payload
~26,330 kg
Extra Height
+30 cm vs standard

The 40ft high cube container is identical to the standard 40ft in footprint but adds approximately 30 centimeters of interior height, bringing the internal height from 2.39 meters to 2.69 meters. This adds around 8 to 9 cubic meters of usable volume. For cargo that is tall, bulky, or needs to be stacked higher than a standard container allows, the high cube is the practical choice. It has become the default container type on many trade lanes, with shipping lines now deploying high cubes as their standard 40ft unit.

Best for:

FurnitureMattressesLarge appliancesAutomotive partsTall or bulky goodsLight high-volume cargo
20ft high cube containers also exist, though they are less common. They offer the same extra 30 cm of height as the 40ft high cube but in the shorter footprint. They are worth asking about if your cargo volume suits a 20ft unit but your goods are tall enough to be restricted by the standard 2.39 meter interior height.

Reefer Containers: Temperature-Controlled Shipping

Reefer Container (Refrigerated)
Available in 20ft and 40ft  |  Active temperature control throughout transit
Temperature Range
-30 to +30 degrees Celsius
40ft Volume (CBM)
~59 cubic meters
20ft Volume (CBM)
~28 cubic meters
Power Source
Ship's power at sea
Monitoring
Continuous temp logging
Humidity Control
Yes adjustable

A reefer container is a thermally insulated shipping container with a built-in refrigeration unit powered by the vessel's electrical supply at sea and by shore power or a generator at port. The refrigeration system maintains a consistent set temperature throughout transit, and most modern reefer units log temperature data continuously so importers and their receivers can verify the cold chain was maintained from origin to destination.

Reefer containers have slightly less usable interior volume than their dry counterparts because the refrigeration equipment occupies space at one end of the unit. A 40ft reefer offers approximately 59 cubic meters of usable space compared to 67 cubic meters in a standard 40ft dry container.

Best for:

Fresh produceMeat and seafoodDairy productsFlowers and plantsPharmaceuticalsTemperature-sensitive chemicals
Pre-cooling is essential for reefer shipments. A reefer container must be pre-cooled to the target temperature before cargo is loaded. Loading warm cargo into a reefer unit that has not reached its set temperature puts the entire shipment at risk. Your freight forwarder should confirm with the origin CFS or stuffing location that pre-cooling was completed before cargo was loaded. Always request the temperature data log at destination as proof of cold chain integrity.

Other Container Types Worth Knowing

Beyond the three primary types, several specialist container configurations are relevant to importers handling cargo that does not fit standard dry containers.

Open Top Container
Available in 20ft and 40ft  |  Removable roof for top-loading cargo

An open top container has no fixed roof. Instead it uses a removable tarpaulin cover, allowing cargo that is too tall to fit through standard container doors to be loaded from above using a crane. The container itself is otherwise identical in footprint to a standard dry container, with the same door opening at one end.

Best for:

Oversized machineryCoils and rollsConstruction equipmentTall cargo exceeding 2.39m
Flat Rack Container
Available in 20ft and 40ft  |  No walls or roof for out-of-gauge cargo

A flat rack container has only a floor and two collapsible end walls, with no side walls or roof. Cargo can be loaded from the sides or from above and can extend beyond the flat rack's dimensions, known as out-of-gauge cargo, subject to carrier approval. Flat racks are used for cargo that simply cannot fit inside any standard enclosed container.

Best for:

Large vehiclesIndustrial pipesYachts and boatsOut-of-gauge machinery

Full Comparison: All Container Types at a Glance

Shipping container types comparison: dimensions, volume, payload and best use
Container TypeInt. LengthInt. HeightVolume (CBM)Max PayloadTemp Control
20ft Standard Dry5.90 m2.39 m~33 CBM~28,200 kgNo
40ft Standard Dry12.03 m2.39 m~67 CBM~26,500 kgNo
40ft High Cube12.03 m2.69 m~76 CBM~26,330 kgNo
20ft Reefer5.44 m2.27 m~28 CBM~27,440 kgYes (-30 to +30C)
40ft Reefer11.59 m2.27 m~59 CBM~29,460 kgYes (-30 to +30C)
20ft Open Top5.90 mNo roof~32 CBM~28,130 kgNo
40ft Flat Rack12.13 mNo wallsPlatform only~40,000 kgNo

How to Choose the Right Container for Your Shipment

The decision follows a clear sequence. Work through these steps before you confirm your booking with your freight forwarder.

1
Does your cargo require temperature control? If yes, you need a reefer container. Determine the required temperature range and whether you need humidity control. No further steps for standard dry containers apply.
2
Does your cargo exceed standard container dimensions? Cargo taller than 2.39 meters requires a high cube or open top. Cargo that cannot fit inside any container requires a flat rack. Confirm dimensions with your supplier before booking.
3
Calculate your total volume in CBM. Under 15 CBM generally favors LCL. Between 15 and 25 CBM a 20ft container is often optimal. Above 25 CBM a 40ft is almost always the right choice. Above 50 CBM consider whether you need a 40ft high cube for the additional volume.
4
Check your total cargo weight against the payload limit. If your cargo is heavy relative to its volume and approaches 25,000 kg, verify the specific carrier's weight limit for your route. Some ports and countries have lower weight limits than the container's rated payload.
5
Confirm with your freight forwarder before booking. Share your exact cargo dimensions, weight, and CBM with your forwarder. They will confirm the right container type, check carrier availability on your specific trade lane, and flag any restrictions that apply to your cargo category.

Container availability also varies by trade lane and by season. On the transpacific route from China to the US, 40ft high cubes are the standard unit on most services, while 20ft containers are more common on routes originating from Southeast Asia and South Asia. Your freight forwarder should confirm what is available on your specific sailing. For a detailed breakdown of transit times on transpacific routes and how container type affects your delivery timeline, our guide on ocean freight transit times from China to the US covers every major route in detail.

Container Type and Documentation Requirements

Your container type affects the documentation your shipment requires. Standard dry container shipments follow the baseline US import documentation requirements: commercial invoice, packing list, Bill of Lading, and ISF filing at least 24 hours before vessel departure.

Reefer container shipments may require additional documentation depending on the commodity. Fresh produce, meat, dairy, and plant products typically require phytosanitary certificates, health certificates, or FDA Prior Notice, depending on the specific goods and their country of origin. Pharmaceutical reefer shipments often require GDP (Good Distribution Practice) documentation and temperature records from the manufacturer. Your customs broker should review the regulatory requirements for your specific reefer cargo before the booking is confirmed.

Open top and flat rack shipments carrying oversized or out-of-gauge cargo typically require a special stowage request from the carrier, which must be approved before booking. The carrier may also require a cargo securing plan confirming how the cargo will be lashed and braced on the container platform. Getting ahead of these requirements prevents last-minute delays at the origin port. Our team at Express Ocean Logistics manages all customs documentation and compliance requirements as part of our ocean freight services, so you have one point of contact covering both the freight and the paperwork.

VGM (Verified Gross Mass) is mandatory for all containers. Under SOLAS regulations, every packed container must have a verified gross mass submitted to the carrier before the container can be loaded onto a vessel. The VGM is the total weight of the cargo plus the tare weight of the container. Your freight forwarder handles VGM submission as part of the booking documentation, but the accurate weight must come from the shipper. An inaccurate VGM can result in the container being rejected at the terminal gate.

Booking the Right Container Through Express Ocean Logistics

Once you know your container type, the next step is securing space on a vessel. Express Ocean Logistics books FCL container space directly with carriers across all major trade lanes, including transpacific, transatlantic, and Asia-to-US East Coast routes. Our FMC-licensed NVOCC status means we hold direct service contracts with carriers, which gives our clients access to consistent space allocations even during peak season when spot market capacity tightens.

For importers whose volumes do not yet justify a full container, we consolidate LCL cargo into our own FCL bookings. If you are still determining whether your shipment suits FCL or LCL, our guide on what a NVOCC does and why it matters explains how consolidation works and the protections that come with shipping through a licensed NVOCC.

Our digital platform gives every client real-time visibility on their container from origin pickup through port discharge and customs release. If you want to see how we manage container bookings, documentation, and tracking in one place, you can explore the platform's capabilities on our digital solutions page.

Frequently Asked Questions About Shipping Container Types

These are the container questions the Express Ocean Logistics team answers most often from importers planning their ocean freight shipments.

What is the difference between a 20ft and 40ft shipping container?
A 20ft standard container has an internal volume of approximately 33 cubic meters and a maximum payload of around 28,200 kg. A 40ft standard container has approximately 67 cubic meters of internal volume and a maximum payload of around 26,500 kg. The 40ft offers roughly double the volume, but its heavier tare weight gives it a slightly lower payload limit. The 20ft suits dense, heavy cargo while the 40ft suits larger volumes of lighter, bulkier goods.
What is a reefer container and what cargo does it carry?
A reefer container is a refrigerated shipping container with a built-in refrigeration unit that maintains controlled temperatures from approximately minus 30 to plus 30 degrees Celsius throughout ocean transit. They are used for perishable goods including fresh fruit, vegetables, meat, seafood, dairy products, flowers, pharmaceuticals, and temperature-sensitive chemicals. Reefer containers are available in 20ft and 40ft sizes and log temperature data continuously throughout the voyage.
What is a high cube container and when do I need one?
A high cube container adds approximately 30 centimeters of internal height compared to a standard container, increasing the 40ft interior height from 2.39 meters to 2.69 meters and adding around 8 to 9 cubic meters of usable volume. High cube containers are the right choice for cargo that is lightweight but voluminous, such as furniture, mattresses, large appliances, and bulky consumer goods. They are also the default 40ft container type on many transpacific trade lanes.
How do I know which container size is right for my shipment?
Start with your total cargo volume in CBM and total weight in kg. Under 15 CBM usually suits LCL. Between 15 and 25 CBM a 20ft container is typically optimal. Above 25 CBM a 40ft is the better choice. If your cargo is tall but light, consider a 40ft high cube. If temperature control is required, you need a reefer. Share your exact specifications with your freight forwarder before booking so they can confirm the right unit for your specific cargo and trade lane.
What is a TEU and how does it relate to container sizes?
TEU stands for Twenty-foot Equivalent Unit and is the industry standard measurement for container capacity. One 20ft container equals 1 TEU. One 40ft container equals 2 TEUs. Shipping lines, port terminals, and freight forwarders use TEU counts to measure vessel capacity and cargo throughput. FCL freight rates are quoted per container rather than per TEU, but understanding TEU helps you read vessel capacity figures and industry statistics accurately.
Can I mix cargo types inside one container?
Yes, you can mix different products in one FCL container as long as the cargo is compatible, the goods share the same temperature requirements if applicable, and the combined weight stays within the container's maximum payload. Hazardous goods have specific segregation rules that must be followed. Temperature-sensitive cargo cannot be mixed with ambient goods in a standard dry container. Your freight forwarder should review your cargo manifest before booking to confirm compatibility and carrier compliance requirements.
Express Ocean Logistics
Ocean Freight and Container Specialists

Express Ocean Logistics is a technology-enabled, FMC-licensed freight forwarding company headquartered in Cranford, New Jersey. With over 20 years of experience managing FCL and LCL ocean freight across all major trade lanes, our team provides ocean freight, air freight, customs brokerage, and warehouse management services for importers across the United States.