Question 1

What is the actual difference between a 20DC and a 40HC?

Accepted Answer

The two formats sit at opposite ends of dry container demand and serve very different jobs. A 20DC (20-foot Dry Container, also called 20'GP) is the workhorse for heavy or dense cargo — short, manageable, easy to spot on a chassis or a small site. A 40HC (40-foot High Cube) is the same length class as a 40DC but one foot taller (9'6" external versus 8'6"), giving roughly 13% more internal cubic capacity than a standard 40DC for the same footprint. The headline trade-off: a 20DC carries more weight per cubic metre because cargo is denser to its volume, while a 40HC carries more volume per dollar of equipment and per slot on the vessel. If you fill containers by weight, the 20DC wins; if you fill them by volume — which is the case for the majority of dry cargo today — the 40HC wins, and the extra foot of height is the practical reason the format has overtaken the standard 40DC in most lanes.

Question 2

Which should I choose for my cargo: 20DC or 40HC?

Accepted Answer

The decision is driven by your cargo's stowage factor — the ratio of volume to weight. Three rules cover most cases. (1) Dense, heavy cargo (machinery, metal stock, bottled liquids, tiles, dense agri-products): 20DC, because you'll hit the weight limit long before the volume limit, and shipping two 20DCs is often cheaper than one half-empty 40HC on a per-tonne basis. (2) Light, voluminous cargo (furniture, clothing, packaging, foam, light electronics): 40HC, because you'll fill the cube and the extra foot of height matters — pallets stacked two-high in a standard 40DC often have to go single-stacked, while a 40HC accommodates a second tier. (3) Mixed loads or unsure: 40HC by default, because the marginal cost of unused volume is lower than the marginal cost of needing a second container. One pragmatic check: calculate your cargo's total weight and volume, divide one by the other — under roughly 750 kg per cubic metre use 40HC; over that, 20DC starts to win on cost-per-tonne.

Question 3

What are the exact dimensions of a 20DC vs a 40HC?

Accepted Answer

Both formats are ISO-standardised, so the numbers below are consistent across manufacturers within tolerances of a few millimetres. A 20DC measures 6.058 m external length, 2.438 m external width and 2.591 m external height (8'6"); internally it gives 5.898 m length, 2.352 m width and 2.385 m height, with a door opening of 2.343 m wide by 2.280 m high, for roughly 33.2 m³ of internal cube (1,172 ft³). A 40HC doubles the length at 12.192 m, keeps the same 2.438 m external width but stands one foot taller at 2.896 m external (9'6"); internally it measures 12.032 m long, 2.352 m wide and 2.690 m high, with a door opening of 2.343 m × 2.585 m, for 76.4 m³ of internal cube (2,700 ft³) — about 13% more volume than a standard 40DC for the same vessel slot. On weight, a 20DC has a tare of around 2,200-2,300 kg with a max payload near 28,000-28,200 kg, while a 40HC has a heavier tare of 3,900-4,000 kg and a max payload near 26,500-26,700 kg. Two practical notes. First, the max gross weight is identical for both formats at 30,480 kg under standard ISO ratings, so a 40HC's higher tare means its payload is slightly lower than a 20DC's — counterintuitive but important when shipping heavy. Second, road weight limits in most countries cap the loaded container well below the 30,480 kg ISO maximum: a typical road-legal payload sits closer to 21,000-24,000 kg in the EU, and lower in some emerging markets, so always check the local road rule before loading to the theoretical maximum.

Question 4

Why does the 40HC outsell the standard 40DC today?

Accepted Answer

The extra foot of height (9'6" versus 8'6") gives the 40HC about 13% more internal volume than a 40DC for the same external length and the same vessel slot — and at virtually the same shipping cost. For the majority of cargo, that extra cube is free upside: more units per container, fewer containers per shipment, lower per-unit transport cost. The standard 40DC still has its place for cargo that hits weight limits early (where the extra cube wouldn't be used anyway) and for routes with road-height restrictions where 9'6" containers can't be trucked legally — but those constraints are increasingly rare. In most global trade lanes today, the 40HC has become the default 40-foot dry container, and 40DC stock is shrinking accordingly.

Question 5

How do handling, delivery, and site logistics differ between the two sizes?

Accepted Answer

The size difference plays out in three operational dimensions beyond the cargo itself. (1) Site access: a 20DC delivered on a tilt-bed truck needs roughly 18-20 metres of straight access; a 40HC needs about 25-30 metres because of the longer chassis. Side-loader delivery, which lifts and places the box from the side of the truck, is more flexible for a 20DC than a 40HC on tight sites. (2) Ground bearing: empty, a 20DC puts roughly 0.5 t on each of its four corners, with similar per-corner loads for an empty 40HC. Loaded near max payload, those corner loads scale up significantly — your site preparation (concrete pads, compacted gravel, level bearing) needs to take total loaded weight, not empty. (3) Stacking and re-handling: 20DCs nest two-to-one with 40HCs on chassis and on the vessel, which is part of why dual-container shipments often combine the two. On site, a 20DC is much easier to relocate after placement than a 40HC; if you're not sure where the box will end up sitting permanently, that flexibility argues for 20DC.

20DC vs 40HC Size Guide – MG-Atlantic

20DC — 20ft Standard

40HC — 40ft High Cube

How to Choose