Free tool
Steel container loading calculator
Find out how many 20ft or 40ft containers your steel order needs. Sized by payload, because dense cargo like steel is weight-limited, not volume-limited.
Container loading calculator
Containers needed
4
Effective max / box
25.2 t
Avg load / box
25.0 t
Steel is weight-limited, not volume-limited— a container hits its payload cap long before it fills up. Utilisation below 100% accounts for dunnage, uneven piece lengths, and axle-weight road limits. Confirm the exact tare and payload on your carrier's container spec.
Container capacity reference
| Container | Max payload | Volume | Note |
|---|---|---|---|
| 20ft Standard | 28.2 t | 33 m³ | Weight-limited for steel |
| 40ft Standard | 26.7 t | 67 m³ | Same payload cap, more space |
| 40ft High Cube | 26.5 t | 76 m³ | Extra height, similar payload |
Payloads are typical maximums and vary by carrier and container tare weight. Confirm the exact figures on your booking.
Frequently asked questions
How many tonnes of steel fit in a 20ft container?
A 20ft standard container has a maximum payload of about 28 tonnes, and because steel is dense it hits that weight limit long before it runs out of space. In practice most steel shipments load 24–27 tonnes into a 20ft box to stay within payload and road axle-weight limits.
Why can a 40ft container carry barely more weight than a 20ft?
Container payload is capped by the maximum gross weight rating, which is similar for 20ft and 40ft boxes. A 40ft container gives you far more volume but only a slightly higher weight limit, so for dense cargo like steel a 20ft box is often loaded to nearly the same tonnage.
Is steel shipping weight-limited or volume-limited?
Weight-limited. Steel's density means a container reaches its payload cap while still mostly empty by volume. That is why this calculator sizes shipments by payload rather than by how much space the steel occupies.
Know the weight before you ship
Use the steel weight calculator to get the tonnage for your order first.