20ft vs 40ft shipping container — which one you actually need

The raw comparison

Both containers are the same width and, in general purpose form, the same height. The only dimension that changes is length. That sounds simple and it is, right up until the truck has to get in.

	20ft general purpose	40ft general purpose
External length	6.06 m	12.19 m
External width	2.44 m	2.44 m
External height	2.59 m	2.59 m
Internal length	5.90 m	12.03 m
Internal width	2.35 m	2.35 m
Internal height	2.39 m	2.39 m
Door opening	2.34 m wide, 2.28 m high	2.34 m wide, 2.28 m high
Cubic capacity	33.2 m³	67.7 m³
Tare weight	approx 2,200 kg	approx 3,800 kg
Floor area	approx 13.9 m²	approx 28.3 m²

Note the tare figures. The 40ft holds twice the volume but weighs well under twice as much empty, because a container is mostly a frame with skin stretched over it and the frame does not double. The full reference for every size, including high cubes, is on the dimensions page.

Cost per cubic metre

We are not going to put figures in a guide, because they move with grade, condition and availability, and the number that matters to you is the one on your quote. But the shape of it is consistent and worth understanding.

Per cubic metre of storage, the 40ft is the cheapest container on the market, the 20ft sits above it, and the 10ft sits well above that. Buying a 40ft rather than two 20fts of the same grade will always be the cheaper way to acquire the same volume, and it will usually be the cheaper way to have it delivered as well, because one delivery is one delivery.

Compare the actual current numbers side by side on our 20ft and 40ft pages. The gap is real and it is the reason people talk themselves into the bigger box.

Where the 40ft argument falls over

Volume per dollar is only one of the numbers in this decision. The others are all about the site.

It needs a great deal more room to place

A 20ft delivered on a tilt-tray wants roughly twenty metres of straight, level run behind the placement spot. A 40ft on a tilt-tray wants a lot more than that, and the truck itself is longer, so the turn off the street is harder as well. Plenty of suburban blocks that take a 20ft without drama simply cannot take a 40ft on a tilt-tray at all.

The workaround is a side loader or a crane truck, both of which handle 40fts routinely. A side loader does not need a run-in — but it sets the container down off its right-hand side, the driver's side, so the truck has to be able to stand with that side facing the spot. On a narrow street, a one-way street or a driveway that can only be approached from one direction, that is not always possible. The delivery page goes through what each truck needs.

It has to fit where it lands, permanently

Twelve metres is a long object. On a standard residential block it will often cross the whole depth of the backyard or run past a boundary setback. It fixes the shape of the site around it in a way a 20ft does not. Before deciding, peg twelve metres out on the ground and stand back. People are routinely surprised.

It is harder to move later

If you ever need to shift it — a new shed going in, a subdivision, a move, a sale — a 40ft is a bigger, more expensive, more restricted job than a 20ft, and the number of yards and trucks that can handle it is smaller. That is a cost you will not see on day one.

It is a harder resale

The second-hand market for 20fts is deep. Almost anyone can take one. The market for 40fts is thinner, because the same access problem that applies to you applies to the next buyer. If you expect to sell it on in a few years, that matters.

When two 20fts beat one 40ft

• The site cannot take a 40ft. The most common reason, and the only one that ends the argument on its own.
• You want the storage in two places. Two sheds, two yards, one at the house and one at the block.
• You want separation. Clean gear in one, dirty gear in the other. Chemicals away from feed. Tools away from the tenant. You cannot do that in one long box without building a wall.
• You want two door ends. A 40ft has doors at one end and twelve metres of depth behind them. Everything at the back needs everything at the front moved first. Two 20fts give you two openings and much better access to the whole volume.
• Staged spend. Buy one now, one later, without committing everything at once.
• You may want to sell one later. Easier to sell one 20ft than half a 40ft.

When one 40ft is clearly right

• Long items. Timber, pipe, ladders, racking, rowing shells, kayaks, roof sheets. Anything over six metres physically will not go into a 20ft, and this decides the question outright.
• Industrial or rural sites with room. Wide gateways, hardstand, no overhead lines, a truck that can drive a loop. The access objection disappears and the cost advantage stands.
• Genuinely large volume. If you know you need something near seventy cubic metres, two 20fts cost more, take two deliveries and give you two sets of doors to secure.
• One footprint, not two. On a site where the container is an eyesore to be tucked away, one long unit along a boundary is often less intrusive than two boxes in the middle of things.

Do not forget the 10ft and the high cube

The choice is not binary. If the honest answer is that you need somewhere lockable for a mower, a compressor and a rack of hand tools, a 10ft will do it, fit through a gap a 20ft cannot, and leave your yard usable. It costs more per cubic metre and is worth every cent when the alternative does not fit.

In the other direction, a high cube adds 300 mm of internal height for a modest premium and no extra footprint. If you are storing anything tall, racking anything, or thinking about a fit-out where the ceiling will come down once you line it, the high cube is usually the better buy at either length. It is taller to deliver, though, so check overhead clearance on the route.

A quick way to decide

1. Measure the longest thing going in. Over 5.9 m internal and the 20ft is out, no further discussion.
2. Peg out the footprint on the ground where it will actually sit, with the door swing allowed for — around 2.5 m clear in front of the doors when they are open past ninety degrees.
3. Walk the access as if you were the truck. Entry width, the turn, the run behind the spot, what is overhead.
4. Ask whether you want one opening or two. This is the question people wish they had asked, about a year in.
5. Then compare price. Not before. Price is the easiest part of this decision to fix and the least likely to be the thing you regret.

If you are not sure, send us three photographs — from the road looking in, from the placement spot looking back out, and a wide shot of the spot itself. That is usually enough for us to tell you what will physically go in there. Ring 0477 410 500 and we will talk it through.