1. What CBM Means
CBM stands for cubic metre. It is the amount of space your cargo occupies after packing. For LCL shipments, carriers and consolidators commonly price by CBM rather than by piece count.
The basic formula is length × width × height in metres. If your measurements are in centimetres, divide by 1,000,000 after multiplying.
2. Why Air Freight Uses Volumetric Weight
Airlines sell limited aircraft space. A shipment that is light but bulky still consumes space, so volumetric weight is used to create a fair billing method for capacity planning.
A common formula is: length × width × height in centimetres ÷ 6,000. The result is the volumetric weight in kilograms.
3. Chargeable Weight Is the Billing Weight
Chargeable weight is whichever is higher: gross weight or volumetric weight. If a cargo weighs 150 kg but calculates to 200 kg volumetric, the carrier usually bills 200 kg.
Worked example: 10 cartons sized 60 × 40 × 50 cm each produce 2.0 CBM in total. In air freight, each carton gives 20 kg volumetric weight, so the shipment could be billed at 200 kg even if the actual weight is only 150 kg.
4. How This Affects Sea Freight
For sea freight, CBM is the more important number for LCL planning. If your shipment is dense, sea freight often works in your favor. If it is bulky and urgent, air freight can become expensive very quickly.
5. Reduce Surprises Before Booking
- Measure packed dimensions, not product dimensions.
- Ask your supplier for carton-level packing details before the final quote.
- Compare the air-freight and sea-freight break-even point on real package data.
- Use the CBM Calculator before approving freight.
6. Use CBM for Better Mode Selection
Once volume is clear, it becomes easier to decide whether the shipment belongs in air, LCL sea, or FCL sea. That decision should happen before dispatch, not after cargo reaches the terminal.