What is CBM?
CBM stands for Cubic Meter (m³), the standard unit of volume used in international shipping and freight. It measures the amount of space a shipment occupies, calculated by multiplying length, width, and height in meters.
Shipping companies, freight forwarders, and customs agencies worldwide use CBM to determine freight charges. Whether you are shipping by ocean (FCL or LCL), air cargo, or road freight, CBM is the primary volume measurement for pricing.
One cubic meter equals 35.3147 cubic feet, 1,000 liters, or approximately 264.17 US gallons. A standard pallet (120 × 100 × 150 cm) occupies about 1.8 CBM. Understanding CBM helps you optimize container loading and reduce shipping costs.
How to Calculate CBM
CBM calculation is simple: convert all measurements to meters, then multiply them together.
Step 1: Measure the length, width, and height of your package or cargo.
Step 2: Convert all measurements to meters. Divide centimeters by 100, divide inches by 39.3701, multiply feet by 0.3048.
Step 3: Multiply length × width × height to get CBM.
Step 4: For multiple identical packages, multiply CBM by the quantity.
Worked Example
A carton measures 60 cm × 40 cm × 30 cm. You have 50 cartons, each weighing 12 kg.
CBM per carton: 0.60 × 0.40 × 0.30 = 0.072 CBM
Total CBM: 0.072 × 50 = 3.6 CBM
Total Weight: 12 × 50 = 600 kg
Unit Conversion Factors to Meters
| From | To Meters |
|---|---|
| Centimeters | Divide by 100 |
| Inches | Divide by 39.3701 (or multiply by 0.0254) |
| Feet | Multiply by 0.3048 |
CBM for Common Shipping Containers
Standard ISO shipping container capacities. Note that usable internal volume is slightly less than rated capacity due to container walls and door openings.
| Container Type | Internal Dimensions (L×W×H) | Capacity (CBM) | Capacity (ft³) | Max Payload (kg) |
|---|---|---|---|---|
| 20-ft Standard | 5.90 × 2.35 × 2.39 m | 33.2 CBM | 1,172 ft³ | 21,770 kg |
| 40-ft Standard | 12.03 × 2.35 × 2.39 m | 67.7 CBM | 2,390 ft³ | 26,680 kg |
| 40-ft High Cube | 12.03 × 2.35 × 2.69 m | 76.3 CBM | 2,694 ft³ | 26,330 kg |
| 45-ft High Cube | 13.56 × 2.35 × 2.69 m | 85.7 CBM | 3,026 ft³ | 25,600 kg |
Unit Conversion Reference
Frequently Asked Questions
What is CBM in shipping?
CBM stands for Cubic Meter and is the standard volume measurement used by shipping lines, freight forwarders, and logistics companies worldwide. It determines how much space your cargo occupies in a container, truck, or aircraft. Freight charges for LCL (Less than Container Load) ocean shipments are typically quoted per CBM.
How do I calculate CBM from centimeters?
Divide each dimension (length, width, height) by 100 to convert centimeters to meters, then multiply all three. For example, a box 50 cm × 40 cm × 30 cm: (50/100) × (40/100) × (30/100) = 0.5 × 0.4 × 0.3 = 0.06 CBM. Alternatively, multiply all three in cm and divide by 1,000,000.
How many CBM fit in a 20-foot container?
A standard 20-foot shipping container has an internal capacity of approximately 33.2 CBM. However, practical usable space is typically 25-28 CBM due to palletization, stacking limitations, and the need for air circulation. The maximum payload weight is about 21,770 kg (48,000 lbs).
What is the difference between CBM and volumetric weight?
CBM measures actual volume, while volumetric (dimensional) weight converts volume into a weight equivalent for pricing. Air freight uses a divisor of 6,000 (CBM × 1,000,000 / 6,000 = volumetric weight in kg). Ocean freight typically charges whichever is greater: actual weight or 1 CBM = 1,000 kg (1 metric ton). This ensures carriers are fairly compensated for bulky, lightweight goods.
How do I convert CBM to cubic feet?
Multiply CBM by 35.3147 to get cubic feet. For example, 2.5 CBM × 35.3147 = 88.29 cubic feet. To convert cubic feet back to CBM, divide by 35.3147 or multiply by 0.0283168.
Should I use CBM or weight for freight quotes?
Freight carriers charge based on whichever is greater: actual gross weight or volumetric weight. For ocean freight (LCL), the rate is typically per CBM or per 1,000 kg, whichever yields the higher charge. For air freight, volumetric weight = L(cm) × W(cm) × H(cm) / 6,000 per package. Always calculate both and use the higher figure when estimating costs.