How Many Containers Can a Ship Carry?

The short answer is that the very largest container ships can carry more than 24,000 containers on a single voyage, a figure measured in a unit called the TEU. The current record holder, the MSC Irina, has a capacity of 24,346 TEU. Most ships in service carry far fewer, and the real number of boxes on any given sailing is lower still.

This guide explains how container ship capacity is measured, how many the biggest vessels can hold, and why the headline figure is not quite the full story.

What Is a TEU?

Container ship capacity is measured in TEU, which stands for twenty-foot equivalent unit. One TEU is the space taken up by a single standard 20ft shipping container, and a 40ft container is counted as two TEU. So when a ship is described as having a capacity of 20,000 TEU, that means it can carry the equivalent of 20,000 twenty-foot containers, or 10,000 forty-foot containers, or some mix of the two.

Using TEU as a common measure lets the whole industry compare ships of very different designs on a like-for-like basis, in much the same way that ISO standards let the containers themselves travel anywhere in the world. You can read more about that in our guide to ISO containers.

How Many Containers Can the Largest Ships Carry?

The largest container ships afloat are known as ultra-large container vessels, or ULCVs, and they cluster around the 24,000 TEU mark. At the very top sits the MSC Irina, which entered service in 2023 with a capacity of 24,346 TEU. It measures almost 400 metres long and just over 61 metres wide, and is designed to stack containers as many as 26 tiers high.

A handful of near-identical giants follow close behind, including the MSC Tessa, the Ever Alot and the OOCL Spain class, all sitting within a few hundred TEU of one another at around 24,000 TEU. These ships work the busiest long-haul routes, particularly between Asia and Europe.

Nominal Capacity vs the Real Number of Boxes

There is an important catch to the headline figure. A ship’s stated TEU is a nominal capacity, a theoretical maximum that assumes every slot is filled with a standard, lightly loaded 20ft container. In practice, no ship sails with quite that many laden boxes on board.

Once you factor in weight limits, the mix of heavier 40ft containers, refrigerated units that need power points, and the way cargo has to be balanced across the vessel, the real number carried comes out lower. So while the MSC Irina can nominally hold 24,346 TEU, a typical loaded voyage carries fewer actual containers than that figure suggests. Nominal TEU is best thought of as a measure of a ship’s size, rather than a promise of exact cargo.

Container Ship Sizes, From Feeders to Giants

Not every container ship is a giant. They range enormously in size, and are usually grouped into broad classes:

• Feeder ships are the smallest, carrying roughly 1,000 to 3,000 TEU on shorter regional routes.
• Panamax ships were sized to fit the original Panama Canal locks, at around 3,000 to 5,000 TEU.
• New Panamax ships were built for the widened Panama Canal and carry roughly 10,000 to 14,000 TEU.
• Ultra-large container vessels are the biggest of all, from around 18,000 TEU up to today’s 24,000-plus TEU record holders.

Smaller feeder ships often carry cargo on from the mega-ships at major hub ports, taking it to smaller ports that the giants are too large to reach.

How Did Ships Get So Big?

The first purpose-built container ships of the 1950s and 1960s carried only a few hundred to around a thousand containers. Capacity has climbed steadily ever since, roughly doubling every couple of decades, as shipping lines pursued the greater efficiency that a bigger vessel brings.

None of it would have been possible without standardisation. Because every container is built to the same ISO dimensions and corner fittings, ships, cranes and ports can all be designed around one predictable, stackable unit. You can read more about the record-breaking vessels in our look at the world’s largest container ships.

The Same Box, on Your Site

Every one of those tens of thousands of containers began as a standard steel box, the very same type we supply for storage and site use across Sunderland, the North East, Teesside, Scotland and the Borders. Whether you need a single unit or several, we stock new-build and used containers built to the same ISO standards that make the global shipping system work. Get in touch to find the right one for you.

Frequently Asked Questions

How many containers can a ship carry?

The largest container ships can carry more than 24,000 TEU, or twenty-foot equivalent units. The current record holder, the MSC Irina, has a nominal capacity of 24,346 TEU. Most ships in service are smaller, and the actual number of boxes on any voyage is lower than the nominal figure.

What does TEU mean?

TEU stands for twenty-foot equivalent unit. One TEU is the space of a single 20ft shipping container, and a 40ft container counts as two TEU. It is the standard measure used to describe and compare container ship capacity across the industry.

What is the world’s largest container ship?

As of 2026, the largest container ship by capacity is the MSC Irina, which entered service in 2023 with a nominal capacity of 24,346 TEU. It is nearly 400 metres long and can stack containers up to 26 tiers high, working mainly between Asia and Europe.

Why don’t ships carry their full TEU capacity?

Nominal TEU assumes every slot holds a standard, lightly loaded 20ft container. In reality, weight limits, heavier 40ft units, refrigerated containers and the need to balance the load mean a ship carries fewer actual boxes than its headline capacity suggests.

How big is a container ship?

They vary widely. Small feeder ships carry around 1,000 to 3,000 TEU, mid-sized vessels several thousand more, and the largest ultra-large container vessels exceed 24,000 TEU, measuring close to 400 metres long.