Choosing a container seems like a question of size. In reality, it's a balancing act between two constraints: the volume you need to load and the weight you're allowed to load. Many shippers pick a format that's too big and pay for empty air, or too small and get stuck at loading time.
This article compares the three most commonly used formats on Canada-Africa routes: the standard 20-foot, the standard 40-foot, and the 40-foot High Cube. It explains when each one makes sense, which cargo suits them, and which mistakes to avoid. Exact capacities (interior dimensions, tare weight, maximum payload) vary by container owner and model: they're always shown on the container's data plate and should be checked case by case.
The Core Principle: Volume vs. Weight
A container has two limits:
- A volume limit: the available interior space.
- A weight limit: the maximum authorized payload, shown on the container's data plate, plus any road weight limits between the loading site and the terminal.
Dense cargo (metal parts, liquids, tile, engines) hits the weight limit well before filling the volume. Bulky cargo (furniture, boxed clothing, plastics, packaging) fills the volume well before hitting the weight limit.
The right format is the one that gets you close to both limits at once, without exceeding the weight limit.
The Standard 20-Foot Container
The 20-foot is the most compact format in common ocean freight use. It's especially suited to:
- heavy, dense cargo;
- small volumes that still justify a full container;
- loads where space isn't the main constraint;
- destinations or delivery sites where maneuvering a 40-foot is difficult.
Advantages: generally lower freight cost than a 40-foot, easier to maneuver, faster to load.
Limits: limited volume; with light cargo, you pay for a full container for few cubic metres; the weight limit comes quickly with dense products.
The Standard 40-Foot Container
The standard 40-foot offers roughly double the floor volume of a 20-foot, at a price that isn't usually double. This makes it the reference format for many shipments.
It suits:
- medium to large volumes;
- medium-density cargo;
- mixed loads (boxes, pallets, furniture);
- regular commercial shipments.
Advantages: better cost per cubic metre than a 20-foot in many cases; flexible load planning.
Limits: its payload isn't double that of a 20-foot. With very dense cargo, you'll hit the weight limit well before filling the space. It also needs more maneuvering room for loading and delivery.
The 40-Foot High Cube Container
The High Cube keeps the length of a 40-foot but adds interior height. That extra height changes a lot for light, stackable cargo.
It's especially suited to:
- used clothing bales;
- boxes stacked in multiple layers;
- furniture and bulky items;
- cargo that's voluminous but not heavy.
Advantages: significant extra volume for a generally modest premium over the standard 40-foot.
Limits: the extra height doesn't proportionally increase payload; some height restrictions may apply for road transport at destination. Check by country.
Practical Comparison Table
| Criterion | 20' standard | 40' standard | 40' High Cube |
|---|---|---|---|
| Usable volume | Lowest | About double the 20' | Higher than the standard 40' |
| Ideal cargo | Dense and heavy | Medium density | Bulky and light |
| Freight cost | Lowest | Intermediate | Generally close to the standard 40' |
| Cost per m³ | Often highest | Good | Often best for light cargo |
| Maneuverability | Excellent | Moderate | Moderate |
| Main risk | Running out of space | Exceeding weight | Height restrictions at destination |
Exact volume and payload figures must be read off the data plate of the actual container supplied.
A Four-Step Method for Choosing
- Calculate your real volume. Add up the volume of your boxes, pallets, or bales, then add a 10-15% margin for space lost to dunnage and irregular shapes.
- Calculate your real gross weight, including packaging. Don't estimate it loosely: a weight error has regulatory and financial consequences.
- Compare both against the format you're considering. If weight maxes out before volume, drop a format size. If volume maxes out before weight, move up a format or switch to High Cube.
- Check physical constraints at loading and delivery: access, height, maneuvering room.
An Example
Very light, bulky cargo representing a large volume will rarely hit a weight limit: the High Cube is then the natural candidate. Conversely, compact metal parts will fill a 20-foot's weight limit while leaving space unused: the 20-foot remains the right choice, and the surplus should go into a second container or a separate shipment.
What If I Don't Have Enough Cargo for a Full Container?
This is a common situation, and the answer is consolidation: your lot shares a container with others and you pay based on your volume and weight. The full comparison is in the article FCL vs Consolidation.
Special Cases
- Vehicles: loading a vehicle into a container follows precise securing rules. See How to Export a Vehicle from Canada to Africa.
- Baled used clothing: the High Cube is often preferred, but the load plan must still respect weight distribution. See How to Pack a Used Clothing Container.
- Oversized cargo: may require specialized equipment (open top, flat rack). Availability depends on the line and destination.
FAQ
Does a 40-foot cost double a 20-foot?
Generally not. A 40-foot's freight is higher than a 20-foot's, but rarely double, which improves cost per cubic metre — provided you fill it.
Can a High Cube carry more weight than a standard 40-foot?
No, the High Cube's advantage is volume, not payload. Check the container's data plate for actual payload.
How do I know how many pallets fit in a container?
It depends on exact pallet dimensions, their height, and whether they can be stacked. A load plan built from your packing list gives a reliable answer.
Can I change the format after booking?
Sometimes, but it depends on equipment availability and can affect the rate. It's better to confirm the format before booking.
What happens if I exceed the payload?
An overloaded container can be refused at the terminal, leading to fees and delays, on top of safety concerns. Declared weight must match reality — see the article on VGM.
Which format should I choose for a personal move?
It depends on the volume of furniture and belongings. A room-by-room inventory helps estimate volume and decide between a 20-foot, a 40-foot, and consolidation.
How do I get a recommendation for my case?
Send your estimated packing list via the Booking page: the right format will be recommended based on the volume/weight pairing and your destination.
A Final Word on Container Selection
When in doubt, it is always safer to share your actual packing list and weight estimate rather than guess at a format from memory. A short conversation before booking can save you from an expensive re-loading or a second shipment later. Treat the volume-versus-weight comparison as a habit for every shipment, not a one-time exercise, since cargo mix often changes from one container to the next.
