Freight & Shipping
20ft vs 40ft Container: Which Should You Use?
Choosing between a 20ft and a 40ft container comes down to your cargo’s volume and weight. Get it wrong and you either pay for space you don’t use or split a shipment that should have travelled together. Here’s how the two compare.
The two standard container sizes
The 20ft and 40ft dry containers are the workhorses of sea freight. They share the same width and height — the 40ft is simply double the length. There’s also the 40ft High Cube, which adds about a foot of internal height for extra volume without extra floor space.
Volume: how much fits
A 20ft container holds roughly 33 CBM of usable space; a standard 40ft holds about 67 CBM, and a 40ft High Cube around 76 CBM. In practice you’ll rarely fill to the theoretical maximum once pallets and packing are accounted for, so plan on usable volume a little below these figures.
Weight: the limit that catches people out
Volume isn’t the only constraint — payload matters. A 20ft container typically takes up to around 24 000 kg of cargo, and a 40ft up to around 30 000 kg. Heavy, dense cargo often hits the weight limit long before the container is full, which is why a 20ft can be the right choice even for a large-looking load.
At a glance
20ft vs 40ft
20ft: ~33 CBM usable · up to ~24 000 kg payload
40ft: ~67 CBM usable · up to ~30 000 kg payload
40ft HC: ~76 CBM usable · extra height, same footprint
Heavy & dense → 20ft. Bulky & light → 40ft.
When to choose a 20ft
Pick a 20ft for heavy, dense cargo, or when your volume is below roughly 25–30 CBM. It’s also the better option when you don’t have enough cargo to justify the cost of a 40ft and want to avoid shipping air.
When to choose a 40ft
Step up to a 40ft (or High Cube) for bulky, lighter cargo where you’ll run out of space before weight. Per cubic metre, a 40ft is usually cheaper than two 20ft containers, so for high-volume shipments it’s the more economical choice.
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