How Many CBM in a 20ft, 40ft & 40HC Container?
Container capacity decides whether your cargo needs an LCL slot, one box or two. Here are the usable CBM figures for every standard dry container, plus how to estimate how much actually fits.
A 20ft container holds about 33 CBM, a 40ft about 67 CBM, a 40ft High Cube about 76 CBM, and a 45ft High Cube about 86 CBM of usable cargo space. These are practical loadable figures — the raw internal volume is slightly higher, but you can realistically fill around 80–90% of it once pallets, packaging and loading access are accounted for.
Usable CBM by container type
The figures below are typical usable volumes — what you can realistically load, not the theoretical maximum. Internal dimensions vary a little between manufacturers, so treat them as planning numbers.
| Container | Internal L × W × H | Usable CBM |
|---|---|---|
| 20ft Standard | 5.90 × 2.35 × 2.39 m | ≈ 33 CBM |
| 40ft Standard | 12.03 × 2.35 × 2.39 m | ≈ 67 CBM |
| 40ft High Cube | 12.03 × 2.35 × 2.69 m | ≈ 76 CBM |
| 45ft High Cube | 13.56 × 2.35 × 2.69 m | ≈ 86 CBM |
High Cube vs Standard
A High Cube container is the same length and width as a standard box but 30 cm taller inside(2.69 m versus 2.39 m). That extra height is why a 40ft HC fits about 76 CBM against a standard 40ft's 67 — roughly 9 extra cubic meters for the same floor space. For tall or stackable cargo, the High Cube is usually the better value per CBM.
Why you can't use every cubic meter
Usable CBM is always less than the geometric internal volume because cargo is not a perfect liquid that pours into corners. Three things eat into it:
Packaging and pallets.A pallet adds ~12–15 cm of dead height under every stack, and cartons leave gaps where their dimensions don't divide evenly into the container.
Carton geometry. If your box is 0.6 m wide and the container is 2.35 m wide, three fit across with 0.55 m wasted. Box dimensions that tile cleanly fill far more.
Loading and bracing.You need room to move goods in and to secure them so they don't shift in transit.
From CBM to number of boxes
A quick ceiling is usable CBM ÷ carton CBM. A 1.0 m cube is 1 CBM, so by pure volume about 33 fit in a 20ft. But geometry gets the last word: laid out 5 long × 2 wide × 2 high, that 1 m cube actually fits 20 to a 20ft — the honest, orientation-based answer. Always sanity-check the volume figure against how the boxes physically stack.
That is exactly what the container loading calculator does — it reports both the volume ceiling and the realistic orientation-based fit. To go via pallets first, see how many boxes fit on a pallet, and to understand the CBM unit itself, read what CBM means in shipping.
Frequently asked questions
How many CBM are in a 20ft container?
A 20ft standard container has roughly 33 CBM of usable space. Its total internal volume is closer to 33–34 CBM, but real loadable volume is a little lower once you account for pallets, packaging and loading access.
How many CBM are in a 40ft container?
A 40ft standard container holds about 67 CBM of usable cargo, and a 40ft High Cube — which is 30 cm taller inside — holds about 76 CBM.
How many CBM are in a 45ft High Cube?
A 45ft High Cube container holds about 86 CBM of usable space, making it the largest standard dry container in common use.
Why is usable CBM less than the container's internal volume?
Cargo is rarely a perfect cube. Pallet footprints, carton dimensions, dunnage and the space you need to load and brace the goods all mean you can fill roughly 80–90% of the raw internal volume in practice.
How do I work out how many boxes fit in a container?
Divide the container's usable CBM by your carton CBM for a rough ceiling, then check it against an orientation-based fit (how the boxes physically stack). Our container loading calculator does both at once.
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