GET /api/cbm?l=120&w=80&h=100&pcs=5What Is CBM?
CBM stands for cubic metre (m³) — the standard unit of volume measurement used in international shipping and logistics. One cubic metre is the volume of a cube measuring 1 metre on each side, equivalent to 1,000 litres.
In freight, CBM determines how much space your cargo occupies in a shipping container, aircraft, or warehouse. It is the primary volume measurement for sea freight pricing (particularly LCL — Less than Container Load) and is used alongside weight to calculate chargeable weight in air freight.
How to Calculate CBM
CBM = Length (m) × Width (m) × Height (m)
If measuring in centimetres:
CBM = (Length × Width × Height in cm) ÷ 1,000,000
For multiple items of the same size:
Total CBM = CBM per item × QuantityFor mixed cargo (different sizes), calculate each item separately and sum the totals.
Important: always measure the outermost dimensions of the packaged goods — including any bulges, protrusions, or irregular shapes. Carriers measure from the widest point.
CBM and Container Capacity
| Container Type | Internal Dimensions | Max CBM | Typical Usable | Max Payload |
|---|---|---|---|---|
| 20ft Standard | 5.90 × 2.35 × 2.39 m | 33.2 m³ | 25–28 m³ | 21,770 kg |
| 40ft Standard | 12.03 × 2.35 × 2.39 m | 67.7 m³ | 55–58 m³ | 26,480 kg |
| 40ft High Cube | 12.03 × 2.35 × 2.69 m | 76.3 m³ | 60–65 m³ | 26,230 kg |
Usable capacity is always less than the maximum internal volume due to pallet gaps, door clearance, and cargo shape. Plan for approximately 80–85% utilisation in practice.
Calculate CBM by Container Type
Select a container or ULD below to open a pre-filled calculator with its internal dimensions.
CBM in Sea Freight Pricing (W/M Rule)
In LCL (Less than Container Load) sea freight, carriers apply the “Weight or Measure” rule:
1 CBM = 1,000 kg (1 freight tonne)The carrier charges based on whichever is greater — the volume in CBM or the weight in tonnes. For example:
- A shipment of 2 CBM weighing 500 kg → charged for 2 CBM (volume is greater: 2 freight tonnes > 0.5 actual tonnes)
- A shipment of 1 CBM weighing 1,800 kg → charged for 1.8 tonnes (weight is greater: 1.8 tonnes > 1 CBM)
This is a much more generous ratio than air freight, where 1 CBM equates to approximately 167 kg. This is why bulky, lightweight goods are almost always cheaper to ship by sea.
CBM vs LDM — When to Use Which
| Measurement | Used For | Unit | When to Use |
|---|---|---|---|
| CBM (Cubic Metres) | Sea freight, air freight, warehouse storage | m³ | International shipping, container loading, volume-based pricing |
| LDM (Loading Metres) | European road freight | Linear metres of trailer floor | UK and EU groupage/part-load road transport |
Road freight in Europe typically prices by LDM (floor space) rather than CBM because trailer height is usually not a constraint — most standard goods don't stack to the roof. Sea and air freight price by volume because container and aircraft space is three-dimensional.
For a detailed LDM calculation, use our Loading Metres Calculator.