How many CBM fit in a 20ft container?
A 20ft container has about 33.1 m³ of internal volume (590 × 235 × 239 cm). In practice you can load about 25–28 CBM of cartons, because boxes leave gaps at the walls, ceiling and door. Plan with 25 CBM for mixed cargo and 28 CBM for uniform, well-sized cartons.
Usable CBM by carton size
| Carton size | Cartons | Loaded CBM | Utilization |
|---|---|---|---|
| 30 × 30 × 30 cm | 931 | 25.1 m³ | 76% |
| 40 × 30 × 30 cm | 781 | 28.1 m³ | 85% |
| 40 × 40 × 40 cm | 350 | 22.4 m³ | 68% |
| 50 × 40 × 30 cm | 472 | 28.3 m³ | 85% |
| 50 × 50 × 50 cm | 176 | 22.0 m³ | 66% |
| 60 × 40 × 40 cm | 262 | 25.2 m³ | 76% |
| 60 × 40 × 50 cm | 223 | 26.8 m³ | 81% |
| 70 × 50 × 50 cm | 149 | 26.1 m³ | 79% |
| 80 × 60 × 60 cm | 75 | 21.6 m³ | 65% |
Utilization depends on how well the carton dimensions divide the container. Sizes that divide evenly, such as 30 × 30 × 30 cm, come close to 76%; awkward sizes leave more empty space.
CBM in cubic feet
33.1 m³ is about 1,170 cubic feet. 25–28 m³ of usable space is about 880–990 ft³.
When to switch to a 40ft
If your shipment is more than about 28 CBM, a single 20ft probably won't hold it, and a 40ft (about 55–60 usable CBM) is usually cheaper than two 20ft containers. Under about 15 CBM, sea freight LCL is often cheaper than a full container.
Frequently asked questions
What is the CBM of a 20ft container?
About 33.1 m³ internal volume; 25–28 m³ is usable for cartons.
How many CBM should I plan for a 20ft container?
Plan 25 CBM for mixed cartons and up to 28 CBM for uniform cartons that fit the container well.
Is 20 CBM enough for a 20ft container?
Yes, 20 CBM of cargo fits comfortably in a 20ft container unless the items are very large or oddly shaped.