How to calculate CBM
CBM (cubic metre) is the volume of your cargo. Multiply length × width × height of one carton in metres, then multiply by the number of cartons:
Example: 50 cartons of 60 × 40 × 35 cm → 0.6 × 0.4 × 0.35 = 0.084 m³ per carton × 50 = 4.2 CBM. If you measure in centimetres, divide L × W × H by 1,000,000.
How many CBM fit in a container?
| Container | Internal volume | Practical loadable CBM* | Max payload |
|---|---|---|---|
| 20ft standard | ≈ 33 m³ | 26 – 28 m³ | ≈ 28,000 kg |
| 40ft standard | ≈ 67 m³ | 56 – 58 m³ | ≈ 26,500 kg |
| 40ft High Cube | ≈ 76 m³ | 66 – 68 m³ | ≈ 26,460 kg |
*Cartons never fill 100% of a container — gaps, door clearance and stacking rules usually leave 10–20% unused. For the real number of cartons, use the container load calculator.
Chargeable weight: LCL sea freight vs air freight
LCL (sea): carriers charge per "revenue ton" (W/M) — whichever is bigger: the volume in CBM or the weight in tonnes (1,000 kg = 1 W/M). 3.5 CBM weighing 900 kg is charged as 3.5 W/M.
Air: volumetric weight = L × W × H (cm) ÷ 6,000 per carton. You pay for the higher of the actual and the volumetric weight. Some couriers use ÷5,000 — check with your forwarder.
Frequently asked questions
How do I convert CBM to cubic feet?
1 CBM = 35.315 cubic feet. Multiply CBM by 35.315.
When is a full container (FCL) cheaper than LCL?
Usually from about 13–15 CBM a 20ft FCL becomes cheaper than paying LCL rates — compare quotes. Read our FCL vs LCL guide.
Is CBM enough to plan a container?
No. Two shipments with the same CBM can need different containers because cartons can't be cut to fill gaps. Use the container capacity calculator or the full ContainerLoad app for an exact load plan.