CBM: how many containers do I need?
CBM (cubic meters) is the quickest way to estimate how many containers a shipment needs. But volume alone can be misleading – weight, stacking and the shape of the cargo decide in the end.
Key facts
- CBM = length × width × height (in m) × quantity
- Usable volume: 20' ≈ 26–28 m³, 40' ≈ 55–60 m³, 40' HC ≈ 65–70 m³
- Check weight too: about 22 t of cargo per container on German roads
- Non-stackable cargo needs floor space, not volume
How to calculate CBM
Multiply length × width × height in meters, then by the number of pieces. Example: a pallet of 120 × 80 × 150 cm = 1.2 × 0.8 × 1.5 = 1.44 m³. 20 of these pallets = 28.8 m³.
How many CBM fit in a container?
- 20' GP: 33 m³ in theory, about 26–28 m³ in practice
- 40' GP: 68 m³ in theory, about 55–60 m³ in practice
- 40' HC: 76 m³ in theory, about 65–70 m³ in practice
The difference comes from gaps between pieces, pallets that cannot be stacked, and space needed for securing. See the exact container dimensions.
Worked example: why CBM is not enough
40 crates of 120 × 100 × 110 cm = 1.32 m³ each, 52.8 m³ in total. By volume this fits into one 40' container.
- Stackable: two layers of 110 cm fit under the 2.39 m ceiling. up to 22 floor positions × 2 layers = 44 places → 1 × 40' is enough.
- Not stackable: at most 22 crates fit on the floor of a 40' → you need 2 × 40', although the volume is only 52.8 m³.
- Heavy: at 600 kg per crate the shipment weighs 24 t – above the ~22 t road limit for one container in Germany.
This is exactly what a load planner does: it checks floor space, height, stacking rules and weight at the same time and recommends the cheapest equipment combination.
CBM and chargeable weight
- Sea freight LCL: 1 m³ = 1,000 kg (W/M) – you pay for whichever is higher.
- Road freight (groupage): usually charged by loading meter or a volume/weight factor of the carrier.
- Air freight: 1 m³ = 167 kg (1 : 6,000).
Values are typical figures for standard equipment. Actual dimensions and limits vary by carrier, container and country – always check with your carrier.
Frequently asked questions
How many CBM are in a 40ft container?
About 67–68 m³ in theory; plan with 55–60 m³ of cargo in practice. A 40ft High Cube has about 76 m³ (65–70 m³ usable).
How many CBM are in a 20ft container?
About 33 m³ in theory, 26–28 m³ usable in practice.
How do I calculate how many containers I need?
Divide the total CBM by the usable volume per container, then check weight (about 22 t per container on German roads) and whether the cargo can be stacked. A load planner like plan4cargo does all three checks at once.