Key Takeaways

• Common sea freight containers include 20’ Dry, 40’ Dry, and 40’ High Cube. The 40’ HC has greater internal height than the 40’ Standard, making it suitable for cargo that requires more space.
• A container’s volumetric capacity does not mean cargo can always be loaded up to the full CBM stated in its specifications. Allowance must be made for Packing, Pallets, stowage arrangements, and weight restrictions.
• Cargo that is tall, oversized, or cannot pass through a standard container door may require an Open Top, Flat Rack, or other Special Equipment.
• Temperature-controlled goods require a Reefer Container, which has less usable internal space than a Dry Container because of its refrigeration system and specialized structure.
• Container dimensions, weight, and Payload can vary by manufacturer and each Shipping Line’s Equipment. Check the actual container specifications before Loading, especially for cargo close to the limits.

What Is a Container?

A Container is equipment designed to pack and transport goods and allow them to be transferred between:

• Truck
• Port
• Vessel
• Rail
• Container Yard

without having to remove the goods from their primary packaging every time the mode of transport changes.

Containers are therefore a key foundation of Intermodal transportation and global Sea Freight.

For businesses, it is not enough to know only:

“Should the cargo use a 20-foot or 40-foot container?”

They should also know:

• How much the cargo weighs
• How many CBM it occupies
• The dimensions of each Package
• The Pallet dimensions
• Whether the cargo is Stackable
• Whether any items are Oversize
• Whether temperature control is required
• How the cargo will be Loaded

These details determine which Container Type is actually suitable.

What Are the Standard Container Sizes?

Common Dry Containers used for imports and exports include:

• 20’ Dry Container
• 40’ Dry Container
• 40’ High Cube Container

Some Shipping Lines also offer other Equipment, such as 45’ High Cube containers. However, for general Shipments, the three sizes above are among the most common options.

The dimensions in this article are approximate values for standard Containers.

Actual containers may vary slightly depending on:

• Manufacturer
• Year
• Shipping Line
• Container Series
• Equipment Design

If Cargo is close to the dimensional or weight limits, check the specifications of the actual container before Loading.

What Is a 20-Foot Container or 20’ Dry Container?

A 20’ Dry Container, also known as a 20’ General Purpose Container, is a standard container commonly used for General Cargo.

Its approximate internal dimensions are:

• Length: approximately 5.9 meters
• Width: approximately 2.35 meters
• Height: approximately 2.39 meters
• Volumetric capacity: approximately 33 CBM

These figures refer to approximate Internal Dimensions, not the container’s external dimensions.

What Types of Cargo Are Suitable for a 20-Foot Container?

It is suitable for cargo such as:

• Machinery Parts
• Metal Products
• Industrial Parts
• Raw Materials
• Tiles
• Hardware
• High-density goods
• Shipments with relatively low Volume but high Weight

Although it has less space than a 40’ container, it can accommodate relatively heavy Cargo within the Equipment’s Payload limit.

However, the following must all be checked:

• Container Payload
• Road Weight Limit
• Port Regulation
• Axle Load
• Weight Distribution

Do not look only at the Maximum Payload shown on the Container and assume that the same weight can be carried on every road Route.

Can a 20-Foot Container Really Hold 33 CBM of Cargo?

Approximately 33 CBM is the container’s estimated geometric internal capacity.

In practice, the usable space for Cargo is often lower because of:

• Cartons
• Pallets
• Packaging
• Gaps between goods
• Loading space
• Cargo shape

For example:

Container Capacity = approximately 33 CBM

This does not mean that 33 CBM of Cargo can always be Stuffed into it.

If the goods are Palletized or cannot be arranged to fill the space efficiently, the actual capacity used will be lower.

What Is a 40-Foot Container or 40’ Dry Container?

A 40’ Dry Container is approximately twice as long as a 20’ container.

Its approximate Internal Dimensions are:

• Length: approximately 12.0 meters
• Width: approximately 2.35 meters
• Height: approximately 2.39 meters
• Volumetric capacity: approximately 67 CBM

It is therefore suitable for cargo with a larger Volume.

What Types of Cargo Are Suitable for a 40-Foot Container?

Examples include:

• Furniture
• Consumer Goods
• Home Decoration
• Textile
• Finished Products
• Packaging
• Plastic Products
• Large quantities of goods with relatively low Weight per CBM

A 40’ container is suitable when a Shipment requires more space than a 20’ container provides.

However, this does not mean it can carry twice the cargo weight of a 20’ container.

Although the Volume is almost doubled, the Maximum Gross Weight does not double in proportion to the available space.

Cargo with a very high Density may therefore reach the Weight Limit before using the full volume.

What Is a 40-Foot High Cube Container or 40’ HC?

A 40’ High Cube, also written as:

• 40’ HC
• 40’ HQ

is similar in length to a 40’ Standard container but is taller.

Its approximate Internal Dimensions are:

• Length: approximately 12.0 meters
• Width: approximately 2.35 meters
• Height: approximately 2.69 meters
• Volumetric capacity: approximately 76 CBM

The main difference is height.

How Much Taller Is a 40’ HC Than a 40’ Standard?

A 40’ Standard container generally has an external height of approximately 8’6”.

A 40’ High Cube is approximately 9’6” tall.

The difference is about:

1 foot, or around 30 centimeters

The additional space helps the High Cube accommodate more cargo by Volume.

What Types of Cargo Are Suitable for a 40’ HC?

It is suitable for cargo that is:

• High in Volume
• Low in Density
• Packed in many Cartons
• Furniture
• Plastic Products
• Consumer Goods
• Textile
• Foam
• Goods requiring additional height

If the goods are bulky but not particularly heavy, a 40’ HC can use space more efficiently than a 40’ Standard.

Should You Choose a 40’ Standard or a 40’ HC?

Consider all of the following:

• Cargo Height
• Total CBM
• Weight
• Pallets
• Freight Rate
• Equipment Availability

If the Cargo occupies approximately 55–60 CBM and is not particularly tall, a 40’ Standard may be sufficient.

However, if the Cargo has a larger Volume or consists of tall Cartons, a 40’ HC can provide additional space.

Do not choose based on CBM alone.

Prepare a:

Loading Plan

to check how each Package can actually be arranged.

What Is the Difference Between CBM and Container Capacity?

CBM is the volume of Cargo.

When dimensions are measured in meters, the formula is:

Width × Length × Height = CBM

Example:

Carton dimensions:

0.5 × 0.4 × 0.3 meters

Volume:

0.06 CBM

For 500 Cartons:

Total Volume =

30 CBM

However, a Total Volume of 30 CBM does not mean that the cargo will occupy exactly 30 CBM of container space with no loss.

Actual stowage depends on the dimensions of both the Cartons and the Container.

Why Might 30 CBM of Cargo Not Fit into a 20’ Container?

Although a 20’ container has an approximate Internal Capacity of 33 CBM, this is a geometric volume.

Suppose the Cartons:

• Cannot be stacked efficiently
• Are placed on Pallets
• Have protruding parts
• Leave Void Space
• Are Non-stackable

The full 30 CBM of Cargo may not fit inside the Container.

It is therefore important to distinguish between:

Theoretical Capacity

and

Usable Cargo Capacity

Do Pallets Affect How Much Cargo Fits in a Container?

Yes, significantly.

When goods are placed on Pallets, some space is taken up by:

• The Pallets themselves
• Gaps between Pallets
• Container Walls
• Loading Clearance

The number of Pallets that can be loaded also depends on the Pallet Standard, such as:

• Euro Pallet
• Standard Pallet
• Pallets with product-specific dimensions

Before Booking an FCL Shipment, provide:

• Pallet Dimension
• Pallet Height
• Gross Weight per Pallet
• Stackable / Non-stackable status

Do not provide only the Total CBM.

What Is Container Payload?

Payload is the Maximum Cargo Weight that a Container is designed to carry according to its specifications.

The basic concept is:

Maximum Gross Weight - Tare Weight = Maximum Payload

Conceptual example:

Maximum Gross Weight = 30,480 kg

Tare Weight = 2,300 kg

Maximum Payload = approximately:

28,180 kg

Actual figures can vary between individual Containers.

Check the following before Loading:

• Container Door
• CSC Plate
• Equipment Specification

What Is Tare Weight?

Tare Weight is the weight of an empty Container.

For example, a 20’ Dry Container may have a Tare Weight of approximately 2.2–2.4 metric tons.

A 40’ container or Special Equipment may weigh more.

To calculate the Container’s Gross Mass, include:

Tare Weight + Cargo + Packing / Securing Material

What Is Maximum Gross Weight?

Maximum Gross Weight is the maximum permitted weight of:

Container + Cargo

according to the Equipment specifications.

However, this must be distinguished from the limits imposed by:

• Trucks
• Roads
• Ports
• Countries
• Routes

Even if a Container can support a high Payload, the Truck transporting it may not legally be able to carry that weight under local regulations.

What Is VGM?

VGM stands for:

Verified Gross Mass

Under the relevant SOLAS requirements, a packed Container must have its total weight verified before it is Loaded onto a Vessel.

VGM includes:

• Cargo
• Packaging
• Securing Material
• Container Tare Weight

Shippers should therefore have accurate actual weight information.

Do not estimate the Container Weight roughly and use that estimate as the Final VGM.

What Other Container Types Are Available Besides Dry Containers?

Not all goods are General Cargo.

Special Containers are available for different Cargo requirements, including:

• Reefer Container
• Open Top Container
• Flat Rack Container
• Platform Container
• Tank Container
• Ventilated Container
• Other Special Equipment

The Cargo requirements should determine the choice.

What Is a Reefer Container?

A Reefer Container, or Refrigerated Container, is designed for goods that require temperature control.

Examples include:

• Frozen Food
• Chilled Food
• Fruit
• Meat
• Seafood
• Certain Pharmaceutical products
• Temperature-sensitive Cargo

A Reefer has an integrated refrigeration system and internal Air Circulation.

As a result, its usable space and container weight differ from those of a Dry Container.

What Sizes Are Available for Reefer Containers?

Common options include:

• 20’ Reefer
• 40’ High Cube Reefer

Dimensions and capacity vary by Shipping Line and Equipment.

Do not use Dry Container dimensions to prepare a Loading Plan for a Reefer.

The internal structure includes:

• Refrigeration Machinery
• T-floor
• Airflow Requirement

which affect the Usable Space.

Can Cargo Be Loaded All the Way to the Reefer Walls?

It should not be.

A Reefer requires Air Circulation in accordance with the Equipment’s operating requirements.

Stuffing must take into account:

• Load Line
• Airflow
• Temperature Setting
• Ventilation
• Product Requirement

Using every available space may prevent effective temperature control.

What Is an Open Top Container?

An Open Top Container has a structure similar to a Dry Container, but its roof can be opened.

It is suitable for Cargo that:

• Is too tall to pass through the Container door
• Must be Loaded from above
• Requires Crane Loading
• Has dimensions unsuitable for a standard container door

Examples include:

• Machinery
• Industrial Equipment
• Heavy Parts
• Project Cargo

After Loading, a suitable Cover can be used to protect the Cargo, depending on the Equipment design.

Is an Open Top Suitable for Cargo That Is Too Tall for a Standard Container?

It is suitable in many cases.

If Cargo exceeds the Container Height, it may be classified as Over-height Cargo.

However, check the following:

• Cargo Height
• Lashing
• Port Handling
• Vessel Stowage
• Route
• Special Surcharge

before Booking.

Over-height Cargo cannot be stacked under other Containers in the same way as General Containers, which affects Space and Freight Cost.

What Is a Flat Rack Container?

A Flat Rack is Equipment with a floor and End Walls but without the Side Walls found on a standard Dry Container.

It is suitable for:

• Oversize Cargo
• Heavy Machinery
• Construction Equipment
• Certain types of Vehicles
• Industrial Equipment
• Project Cargo

Depending on the Shipment arrangement and Carrier approval, Cargo may protrude beyond the:

• Width
• Height

What Sizes Are Available for Flat Rack Containers?

Common options include:

• 20’ Flat Rack
• 40’ Flat Rack
• 40’ High Cube Flat Rack on certain Equipment

Dimensions and Payload vary considerably by Equipment.

Before requesting a Quote, provide accurate Cargo Dimensions and Weight.

What Is a Collapsible Flat Rack?

Some Flat Racks have End Walls that can be folded down.

These are called:

Collapsible Flat Racks

They make it easier to manage space when the Equipment is empty.

For the Shipper, however, it is still important to check:

• Cargo Footprint
• Center of Gravity
• Lashing Point
• Weight Distribution
• Over-width
• Over-height

before Loading.

What Is a Platform Container?

A Platform Container consists of a platform floor without Side Walls or End Walls in the same form as a conventional Container.

It is suitable for:

• Heavy Cargo
• Oversize Cargo
• Project Cargo

that cannot be accommodated in a Dry Container or certain types of Flat Rack.

Using a Platform requires suitable Engineering and Cargo Securing.

Do not choose it simply because the goods are “large” without assessing the Lifting and Lashing Plan.

What Is a Tank Container?

A Tank Container is a tank mounted within a standard Container frame.

It is used for certain Bulk Liquid or Gas products, such as:

• Chemical
• Food-grade Liquid
• Liquid Raw Material

depending on the Tank specifications.

Each product must be checked for:

• Compatibility
• Dangerous Goods Classification
• Cleaning Requirement
• Tank Specification
• Permit

It is Specialized Equipment and should not automatically be treated as a direct substitute for drums in a standard Container.

What Types of Cargo Are Suitable for Dry Containers?

A Dry Container, or General Purpose Container, is suitable for General Cargo that does not require temperature control or specialized Equipment.

Examples include:

• Cartons
• Bags
• Pallets
• Furniture
• Electronics, subject to applicable requirements
• Machinery Parts
• Consumer Goods
• Textile
• Finished Products

However, the term Dry Container does not mean that goods will never be exposed to moisture.

During Sea Transport, the following can occur:

• Humidity
• Condensation
• Container Rain

Goods that are sensitive to moisture still require suitable Packaging and Moisture Protection.

What Is Container Rain?

During a sea voyage, the temperature inside a Container can change with the weather.

Moisture present in the:

• Air
• Cargo
• Wooden Pallet
• Packaging

may condense on the container walls or roof and drip onto the goods.

This is commonly known as:

Container Rain

Goods such as:

• Metal
• Paper
• Textile
• Food Ingredient
• Electronics

may require appropriate Moisture Control planning.

What Should Be Checked When Using Wooden Crates or Wooden Pallets in a Container?

Wood Packaging covered by ISPM 15 may need to undergo treatment and bear the required Mark for International Trade.

Examples include:

• Wooden Pallet
• Wooden Crate
• Dunnage

Before shipping, check:

• Wood type
• ISPM 15 Requirement
• IPPC Mark
• Destination country

Do not wait until after the wooden crates have been built to check the requirements.

Why Is Container Door Opening Important?

Many people look only at a Container’s Internal Dimensions and overlook the Door Opening.

For example, the Container’s internal height may be sufficient for the Cargo, but if the Cargo is taller or wider than the door opening, it cannot pass through the door.

Before arranging a large Shipment, check:

• Internal Length
• Internal Width
• Internal Height
• Door Width
• Door Height

This is particularly important for Machinery and Wooden Crates.

Should Cargo Be Loaded If It Barely Fits Through the Door?

Do not design the Cargo dimensions to fit too closely to the Maximum Door Opening.

Allow clearance for:

• Forklift Movement
• Packing Tolerance
• Container Variation
• Floor Condition
• Loading Angle
• Crate Dimension Variation

Individual Containers can vary slightly in dimensions.

If the clearance is very limited, inspect the actual Equipment or consider a Special Container.

Should Heavy Cargo Use a 20’ or 40’ Container?

Cargo with high Density is often considered for a 20’ container because it uses relatively little space but has a high Weight.

Examples include:

• Metal
• Stone
• Machinery
• Industrial Raw Material

However, it is not correct to conclude that all Heavy Cargo must use a 20’ container.

Consider the following together:

• Total Weight
• Weight Distribution
• Cargo Length
• Loading Method
• Road Limit

Cargo that is longer than a 20’ container may require a 40’ container, even if it is very heavy.

Should Lightweight Cargo with High Volume Use a 40’ HC?

It is often an option worth comparing.

Examples include:

• Furniture
• Foam
• Plastic Products
• Garment
• Consumer Goods
• Packaging

These goods often fill the available space before reaching the Weight Limit.

A High Cube therefore provides additional Cubic Capacity.

How Are LCL and FCL Related to Containers?

LCL

Shipments from multiple Shippers are Consolidated in the same Container.

Charges are based on factors such as:

• Volume
• Weight / Measurement
• Tariff

depending on the Service.

FCL

A Container is primarily allocated to a single Shipper’s Shipment.

Equipment can be selected according to the goods, including:

• 20’ Dry
• 40’ Dry
• 40’ HC
• Reefer
• Special Container

Suggested Internal Link: What Is LCL Sea Freight? Shipping by Sea Without Filling a Container and Which Goods Is It Suitable For?

At What CBM Should You Switch from LCL to FCL?

There is no fixed figure.

The break-even point depends on:

• Route
• Freight Rate
• Origin Charge
• Destination Charge
• Weight
• Commodity
• Container Rate

As Volume increases, request quotes for both:

LCL and FCL

to compare the actual Total Cost.

Even if the Cargo does not fill an entire Container, FCL may still be more cost-effective than LCL.

Can You Choose a 20’ or 40’ Container Based on the Container Rate Alone?

No.

Suppose the Freight Rate for a 40’ container is only slightly higher than for a 20’.

That does not automatically mean the 40’ container is the better choice.

For Heavy Cargo, using a 40’ container may not provide the additional Weight Capacity required.

Conversely, for high-Volume but lightweight Cargo, a 40’ or 40’ HC may reduce Cost per Unit.

Compare the following together:

Cost + Volume + Weight + Loading

What Is a Container Loading Plan?

A Loading Plan is a plan for arranging Cargo inside a Container before Stuffing.

It helps determine:

• What percentage of the space will be used
• How many Pallets will fit
• Whether the Cargo is too tall
• Whether the Weight is distributed appropriately
• How the Cargo will be Loaded and Unloaded
• Whether a Forklift or Crane is required
• Where the Cargo needs to be secured with Lashing

For large Shipments or Machinery, preparing a Loading Plan in advance can significantly reduce problems during Loading.

Why Is Weight Distribution Important?

Heavy Cargo should not be concentrated on one side of a Container without proper planning.

Weight should be distributed appropriately across the Container Floor and considered in relation to:

• Center of Gravity
• Axle Load
• Lashing
• Handling

Improper Weight Distribution can increase risks during:

• Trucking
• Lifting
• Vessel Transport

This is particularly important for Machinery and Metal Cargo.

What Are Cargo Securing and Lashing?

Lashing is the process of securing Cargo to prevent it from moving during Transportation.

Materials and methods may include:

• Strap
• Chain
• Wire
• Blocking
• Bracing
• Dunnage

depending on the goods.

Just because Cargo fits inside a Container does not mean it can be left unsecured.

During a sea voyage, Containers can experience forces caused by:

• Pitch
• Roll
• Vibration
• Acceleration

Cargo must therefore be secured appropriately.

How Much Cargo Can a Container Hold?

The answer should not be based on CBM alone.

At a minimum, consider:

• Container Internal Dimension
• Door Opening
• Maximum Gross
• Tare Weight
• Payload
• Cargo CBM
• Cargo Weight
• Pallets
• Stackability
• Packaging
• Loading Method

For example:

Cargo A = 60 CBM but weighs 8 Tons

It may be suitable for a 40’ or 40’ HC container.

Cargo B = 25 CBM but weighs 25 Tons

Although it has a lower Volume, Weight may be the main constraint.

Are Container Dimensions the Same Across Shipping Lines?

They are similar under standard Equipment specifications, but this does not mean that the dimensions and Weight specifications are identical for every container.

Differences may arise from:

• Manufacturer
• Container Series
• Equipment Type
• Shipping Line

The figures in this article should therefore be used for preliminary planning.

If Cargo is close to the limits, check the Container Specification of the Carrier actually being booked.

Common Mistakes When Choosing a Container

• Looking only at CBM and ignoring Weight
• Assuming a 40’ container can carry twice the Weight of a 20’
• Using Internal Dimensions without checking Door Opening
• Providing Cargo dimensions before Packing
• Forgetting to include Pallets and Wooden Crates
• Assuming Container Capacity equals Usable Cargo Capacity
• Failing to check Stackable / Non-stackable status
• Not preparing a Loading Plan
• Failing to check Weight Distribution
• Using a Dry Container for goods requiring temperature control
• Using standard Equipment for Oversize Cargo without checking dimensions
• Not checking the actual Equipment Payload
• Not checking the Road Weight Limit
• Not checking ISPM 15 for Wood Packaging
• Failing to allow Loading Clearance

Checklist Before Choosing a Container

Before Booking, prepare:

• Product Name
• Number of Packages
• Dimensions after Packing
• Gross Weight
• Total CBM
• Pallet Dimension
• Wooden Crate Dimension
• Stackable / Non-stackable status
• Temperature Requirement
• Dangerous Goods Status
• Over-width / Over-height
• Loading Method
• Unloading Method
• Pickup Location
• Destination
• Equipment Requirement

Then compare which option is suitable:

• 20’ Dry
• 40’ Dry
• 40’ HC
• Reefer
• Open Top
• Flat Rack
• Special Equipment

Frequently Asked Questions About Containers (FAQ)

How Many CBM Can a 20-Foot Container Hold?

Its approximate Internal Capacity is 33 CBM, but the actual Cargo loaded may be less because of Packaging, Pallets, and the stowage arrangement.

How Many CBM Can a 40-Foot Container Hold?

A 40’ Standard has an approximate Internal Capacity of 67 CBM, but its actual Usable Capacity depends on the Cargo and Loading Pattern.

How Many CBM Can a 40’ High Cube Hold?

A 40’ HC has an approximate Internal Capacity of 76 CBM and greater internal height than a 40’ Standard.

What Is the Difference Between a 40’ and a 40’ HC?

The main difference is height. A 40’ HC is approximately 1 foot taller than a Standard container and therefore has greater Cubic Capacity.

Should Heavy Cargo Use a 20-Foot or 40-Foot Container?

This depends on the dimensions and Weight Distribution. For Heavy Cargo with relatively low Volume, a 20’ container is often worth comparing because there may be no need to pay for unused space.

Can 30 CBM of Cargo Fit in a 20’ Container?

CBM alone is not enough to determine this. Although the container has a geometric capacity of around 33 CBM, Package Dimensions, Pallets, and the Loading Pattern must also be considered.

Are the Internal Dimensions of Reefer and Dry Containers the Same?

No. The refrigeration system and internal structure mean that a Reefer has different Usable Space from a Dry Container.

What Should Be Used for Cargo That Is Too Tall for a Standard Container?

An Open Top or Flat Rack may be suitable, depending on Height, Width, Weight, and the Loading method.

Are Container Dimensions the Same for Every Shipping Line?

They are similar under standard specifications, but they can vary slightly by Manufacturer and Equipment. Check the actual container specifications if the Cargo is close to the limits.

Container Shipping Services with CPL INTER

CPL INTER provides international Sea Freight services, including:

• LCL
• FCL

and can coordinate Transportation for General Cargo as well as Shipments that require Equipment to be assessed according to the Cargo characteristics.

Before requesting a Container quote, prepare:

• Product name and photos
• Number of Packages
• Dimensions after Packing
• Gross Weight
• Total CBM
• Pallets / Wooden Crates
• Stackable / Non-stackable status
• Origin
• Destination
• Cargo Ready Date
• Temperature Requirement
• Oversize Dimensions, where applicable

The CPL INTER team can help assess whether a 20’, 40’, 40’ HC, or another type of Equipment is appropriate for the Shipment.

Tel: 02-519-4426 / 091-519-4426
LINE: @cplinter

Written by: CPL Inter Logistics Operations Team, specialists in international freight and customs procedures, with more than 15 years of experience and a commitment to internationally recognized quality management under ISO 9001:2015.