How many CBM fit in a 20ft or 40ft container?
A 20ft container has about 33 CBM of space inside, a 40ft about 67.7 CBM and a 40ft High Cube about 76.4 CBM. You will not load all of it. In the six carton sizes tested below, a 20ft took 24 to 29 CBM of cartons, a 40ft 50 to 61 CBM and a 40ft High Cube 58 to 67 CBM. This guide gives the container sizes, explains why some space is always lost, and shows how to work out the figure for your own cartons.
Quick answer: CBM per container
| Container | Internal volume | CBM of cartons loaded in our tests |
|---|---|---|
| 20ft Standard | 33.2 m³ (1,172 ft³) | 24.4 to 29.1 m³ (73% to 88%) |
| 40ft Standard | 67.7 m³ (2,390 ft³) | 50.4 to 60.6 m³ (74% to 90%) |
| 40ft High Cube | 76.3 to 76.4 m³ (about 2,694 ft³) | 57.6 to 67.3 m³ (75% to 88%) |
The loaded figures come from the CBM Calculator, with one carton size per container, cartons kept upright, and no pallets. The six carton sizes and the result for each are in the worked examples below. Your own figure depends on your carton size, so treat the range as a guide, not a promise.
Container sizes
These are the sizes Hapag-Lloyd publishes for its standard dry containers. Other shipping lines and container makers give figures within a few millimetres of these, so check the size on your booking if the load is tight.
| Container | Inside (L × W × H) | Door opening (W × H) | Capacity | Max payload |
|---|---|---|---|---|
| 20ft Standard | 5,900 × 2,352 × 2,395 mm | 2,340 × 2,292 mm | 33.2 m³ | 28,130 kg |
| 40ft Standard | 12,032 × 2,352 × 2,395 mm | 2,340 × 2,292 mm | 67.7 m³ | 28,750 kg |
| 40ft High Cube | 12,032 × 2,350 × 2,700 mm | 2,340 × 2,597 mm | 76.3 m³ | 28,600 kg |
The calculators on this site use typical internal sizes of 5,898 × 2,352 × 2,393 mm (20ft), 12,032 × 2,352 × 2,393 mm (40ft) and 12,032 × 2,352 × 2,698 mm (40ft High Cube), and a lower, more cautious payload. The difference in volume is less than 0.1 m³.
A 40ft High Cube has the same floor as a 40ft Standard. The extra 8.7 m³ is all height, about 30 cm more. It helps when your cartons can be stacked one layer higher, but it does not add a single floor position for pallets.
Why you cannot use all the CBM
- Cartons do not divide evenly into the container. A 30 cm tall carton stacks 7 high in a standard container: 2.10 m of cartons in 2.39 m of height, so 29 cm above the load is empty. The same happens along the width and length.
- The door is lower than the inside. In a standard container the door opening is about 10 cm lower than the inside height, so the top layer can be hard to load at the door end.
- Upright only. Most cartons must stay “this way up”. That removes the option of laying some on their side to fill a gap.
- Stacking strength. If the bottom cartons cannot carry a full stack, you load fewer layers.
- Pallets. A pallet base is usually around 15 cm tall and the gaps between pallets are lost, so a palletised load uses less of the volume than loose cartons.
- Weight. Heavy goods reach the payload before the space is full. In that case the weight, not the CBM, decides how much you can ship.
Worked examples: six carton sizes
Each row is one carton size loaded on its own, cartons upright, no pallets, worked out with the CBM Calculator. The figures are cartons, CBM loaded and the share of the container used.
| Carton (cm) | 20ft Standard | 40ft Standard | 40ft High Cube |
|---|---|---|---|
| 60 × 40 × 30 | 364 cartons, 26.2 m³, 79% | 770 cartons, 55.4 m³, 82% | 880 cartons, 63.4 m³, 83% |
| 40 × 30 × 30 | 770 cartons, 27.7 m³, 84% | 1,610 cartons, 58.0 m³, 86% | 1,840 cartons, 66.2 m³, 87% |
| 50 × 40 × 30 | 406 cartons, 24.4 m³, 73% | 840 cartons, 50.4 m³, 74% | 960 cartons, 57.6 m³, 75% |
| 45 × 35 × 25 | 738 cartons, 29.1 m³, 88% | 1,539 cartons, 60.6 m³, 90% | 1,710 cartons, 67.3 m³, 88% |
| 60 × 40 × 40 | 260 cartons, 25.0 m³, 75% | 550 cartons, 52.8 m³, 78% | 660 cartons, 63.4 m³, 83% |
| 55 × 45 × 35 | 318 cartons, 27.5 m³, 83% | 654 cartons, 56.7 m³, 84% | 763 cartons, 66.1 m³, 87% |
The 50 × 40 × 30 cm carton shows how much the size matters: it is a common carton, yet it uses only about three quarters of each container, because of the gaps its sizes leave in the container, including 29 cm above the top layer. The 55 × 45 × 35 cm carton, only 5 cm bigger each way, uses about 83%. If you can choose the carton size, test a few options in the calculator before you order cartons.
The 60 × 40 × 40 cm carton gains the most from a High Cube: it stacks 5 high in a standard container but 6 high in a High Cube, so it loads 20% more cartons in the same floor area.
How to work out the CBM for your shipment
- Measure the outside length, width and height of one carton, including any bulge.
- Work out the CBM of one carton: length × width × height in metres. A 60 × 40 × 30 cm carton is 0.6 × 0.4 × 0.3 = 0.072 m³.
- Multiply by the number of cartons to get the total CBM of the shipment.
- Compare it with the loaded figures above, not with the full container volume. If the total is close to the limit, check the real fit in the CBM Calculator, which also handles mixed carton sizes.
- If the goods go on pallets, check the pallets instead with the Container Loading Calculator and the guide to pallets in a container.
Common questions
How many CBM is a 20ft container?
About 33.2 CBM inside. With loose cartons you can usually expect to load less: 24 to 29 CBM in the six examples above.
How many CBM is a 40ft container?
About 67.7 CBM inside a 40ft Standard and 76.3 to 76.4 CBM inside a 40ft High Cube. The examples above loaded 50 to 61 CBM in a 40ft Standard and 58 to 67 CBM in a High Cube.
Is a 40ft container twice a 20ft?
Slightly more than twice in volume: 67.7 against 33.2 CBM, because one 40ft container has two end walls, where two 20ft containers have four. The payload is about the same, so a heavy load does not double.
Do I need a 40ft High Cube?
Only if your cartons gain a full extra layer in the extra 30 cm of height, or the goods are tall. If they do not, a High Cube carries the same number of cartons as a 40ft Standard.
How do I convert container CBM to cubic feet?
Multiply by 35.315. 33.2 CBM is about 1,172 cubic feet and 67.7 CBM about 2,390 cubic feet.
Sources
- Hapag-Lloyd, 20′ Standard container specifications.
- Hapag-Lloyd, 40′ Standard container specifications.
- Hapag-Lloyd, 40′ Standard High Cube container specifications.
- Loaded figures: WarehouseCalc CBM Calculator, tested 14 October 2026. See the methodology for how it loads cartons.