CBM calculator
CBM (cubic meters) is length × width × height in meters, multiplied by the number of cartons. A 60 × 40 × 40 cm carton is 0.096 CBM, so 50 of them are 4.8 CBM, or about 170 cubic feet.
- Carton size 1
- Carton size 2
10.20CBM
360.2 cubic feet across 170 cartons
- Gross weight
- 1,320 kg
- 2,910 lb
- Air chargeable
- 1,700 kg
- by volume, over the gross weight
- Sea freight
- 10.20 W/M
- charged on volume
20 ft standard33.2 m³ inside
31%of one container
40 ft standard67.7 m³ inside
15%of one container
40 ft high cube76.3 m³ inside
13%of one container
How to calculate CBM
- Measure each carton’s length, width and height in centimeters, at the widest points.
- Multiply them and divide by 1,000,000. That is the carton’s volume in cubic meters.
- Multiply by the number of cartons of that size.
- Add every carton size together for the shipment’s total.
Inches? Switch the units and the calculator converts for you. Shipping parcels rather than freight? Use the dimensional weight calculator and check the box against carrier size limits.
What the volume costs by air and by sea
Air freight: chargeable weight
Under IATA’s general rule, each carton’s volume in cubic centimeters divided by 6,000 is its volumetric weight in kilograms. The airline charges whichever is greater, the volumetric weight or the gross weight. Some carriers use a different divisor, so check your quote.
1,700 kg by volume against 1,320 kg gross: charged on 1,700 kg
Sea freight: weight or measure
Less-than-container-load ocean freight is priced per revenue ton, the greater of the volume in cubic meters and the weight in metric tons. One cubic meter counts the same as 1,000 kg, which is why light, bulky goods pay on volume.
10.20 CBM against 1.32 t: charged on 10.20 W/M
How many CBM fit in a container
Inside volume from Maersk’s published dimensions; containers vary a little. Cartons never fill every centimeter, so count them with the container loading calculator before you book.
| Container | Inside length × width × height | Inside volume | Your load |
|---|---|---|---|
| 20 ft standard | 5.896 × 2.350 × 2.393 m | 33.2 m³ | 31% |
| 40 ft standard | 12.032 × 2.350 × 2.393 m | 67.7 m³ | 15% |
| 40 ft high cube | 12.032 × 2.350 × 2.697 m | 76.3 m³ | 13% |
Common questions
How do I calculate CBM?
Measure each carton in centimeters, multiply length × width × height and divide by 1,000,000 to get cubic meters. Multiply by the number of cartons, then add every carton size together.
How do I convert CBM to cubic feet?
Multiply cubic meters by 35.3147. 10 CBM is about 353 cubic feet. To go the other way, divide cubic feet by 35.3147.
How is air freight chargeable weight calculated?
Under IATA’s general rule, divide each carton’s volume in cubic centimeters by 6,000 to get its volumetric weight in kilograms. The shipment is charged on whichever is greater, the volumetric weight or the actual gross weight. Some carriers use a different divisor, so check your quote.
What does W/M mean in sea freight?
W/M means weight or measure. Less-than-container-load ocean freight is charged per revenue ton, which is the greater of the volume in cubic meters and the weight in metric tons (1,000 kg).
How many CBM fit in a 20 ft or 40 ft container?
From Maersk’s published inside dimensions, a 20 ft standard holds about 33.2 cubic meters, a 40 ft standard about 67.7 and a 40 ft high cube about 76.3. Cartons never fill every centimeter, so plan on loading less than that.
Sources
- IATA, Air Cargo Tariffs and Rules: What You Need to Know
- Maersk, dry container equipment specifications
Checked 2026-10-28. Rules change; confirm with the carrier or agency before you rely on a number.
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