What are the dimensions and weight limit of a 20ft dry container?

A standard 20ft dry container is approximately 5.9m long, 2.39m tall, and 2.35m wide, giving roughly 33 cubic meters of volume, with a maximum payload of around 28 tons.

Why shouldn’t you pack a container like a game of Tetris?

Fitting everything inside tells you nothing about center of gravity, axle weight distribution, or whether the cargo will shift during transit. A proper load plan optimizes the floor layout first, then checks weight balance and stacking — not just whether the doors close.

Which cargo should go at the front of a container?

The heaviest cargo should go deepest, toward the front wall — a common-practice rule sometimes summarized as "heavy goes the deepest." This helps pull the center of gravity forward and keeps it lower and more stable.

Can you stack heavy boxes on top of lighter ones?

No — the rule is the opposite. Heavier cargo goes on the floor, and lighter cargo stacks on top of it, for a lower and more stable center of gravity. Whether an item can be stacked on at all also depends on its material and maximum bearable weight; fragile goods often can’t be stacked under anything.

Why is photographing the finished load important?

A photo of the completed load taken in the warehouse is important documentation, and it becomes critical evidence if there’s ever a damage or insurance claim after the shipment moves.

You're Packing Your 20ft Container Wrong. Here's the Right Way.

Most people pack a 20ft container like a game of Tetris — fill it from the back and hope the doors close. Tetris doesn’t account for center of gravity, axle limits, or cargo that shifts mid-voyage.

Key takeaways

A standard 20ft dry container measures 5.9m long, 2.39m tall, and 2.35m wide — about 33 cubic meters and up to 28 tons of payload.
Packing "Tetris-style" — filling from the back and hoping the doors close — ignores center of gravity, axle weight distribution, and cargo movement during transit.
The heaviest cargo belongs deepest, toward the front wall — the common-practice rule is "heavy goes deepest" — which also helps balance the longitudinal center of gravity.
Heavy items go on the floor, lighter items stack on top of them, not the other way around, for a lower and more stable center of gravity.
A good load plan is dynamic: adding even two more items can completely reshuffle the optimal layout, so the plan should be re-checked every time the cargo list changes.
Before the doors close, check for void spaces (especially toward the back wall and on top) and close them with dunnage, airbags, or bracing to prevent cargo movement and damage.
Always photograph the finished load in the warehouse — it is critical documentation for any later damage or insurance claim.

The Problem with Packing Like It's Tetris

The default way most people load a 20ft container is to treat it like a game of Tetris: fill every gap from the back forward and call it done once the doors close. The problem is that fitting everything inside isn’t the finish line. A load plan also has to account for weight distribution, stacking rules, and how the cargo will behave once the container is moving — none of which "does it fit?" tells you.

20ft Dry Container: Dimensions and Limits

Before loading anything, you need to know exactly what you’re working with. A standard 20ft dry container runs 5.9m in length, 2.39m in height, and 2.35m in width — roughly 33 cubic meters of usable volume — and can carry up to approximately 28 tons of cargo.

Start with the Floor Plan, Not the Door

With an example load — ten smaller boxes, two heavy boxes, and a few more mixed items — the first check isn’t whether everything fits, but whether the layout is optimal for what you actually care about, whether that’s space, weight, or price. In this example, the initial layout leaves the longitudinal center of gravity slightly off — still within tolerance, but avoidable. Instead of "playing Tetris," the goal is to optimize the floor layout itself: here, for the fewest loading meters (5.6 down to 4.6), since loading meters is one common way carriers price a shipment.

Stacking Rules: Heavy Goes Deep & Low

Once the floor layout is set, two rules govern everything that goes on top of it. First: heavy cargo goes below light cargo, never the reverse — a one-ton box on the floor can carry smaller 100kg boxes stacked above it, but not vice versa. Second: the heaviest cargo overall goes to the front wall — the deepest position in the container — which is standard practice and also pulls the center of gravity forward and down. Together, these two rules aim for a lower center of gravity and a layout that resists cargo movement when the container is on rough water or being handled at a rail yard.

A Good Load Plan Balances Space and Weight

A good loading plan is a balance between space utilization and weight distribution, not a maximization of either one alone. In the example, moving just two small boxes slightly improves the center of gravity further, even after the main floor layout was already set. Whether you push for more stacking depends on who you are: a shipper generally loads to their own order; a carrier looking to maximize a shipment has more room to stack and consolidate — in this example, weight utilization sat at only around 30%, with volume utilization only slightly higher, meaning roughly two-thirds of the container’s capacity was still unused.

What Determines Whether Cargo Can Be Stacked

Stacking opportunity depends entirely on the cargo itself: what the material is, whether it’s stackable at all, and if so, what maximum weight it can bear on top. Fragile goods often can’t be stacked under anything. This is also why a load plan is a dynamic thing, not a one-time calculation — adding even two more items to the same cargo list can completely change what the optimal layout looks like, since the best arrangement depends on the full list, not just the items placed so far.

Fixing the Center of Gravity

As more cargo is added and the layout is re-optimized, the center of gravity keeps shifting and needs to be re-checked, not assumed. The goal throughout stays the same: keep the load balanced enough that it won’t create axle or handling problems in transit, while still using the container’s volume and weight capacity efficiently.

Void Spaces, Dunnage & Final Documentation

After the cargo is placed, the next check is for gaps — void spaces, commonly found toward the back wall and on top of the load. These are a real damage risk: cargo can shift into them during shipment or during train and port handling. Void spaces should be closed with dunnage, airbags, or bracing material before the load is considered finished. The final step is a full review: confirm proper weight distribution, confirm there are no unaddressed gaps, confirm the doors close cleanly, and verify stack stability. And once the load is done in the warehouse, always take a photograph of the finished cargo — it matters for documentation, and even more so for any damage claim down the line.