CBM to KG Calculator
Convert cubic meters (CBM) to kilograms (kg) using a density or freight conversion factor.
How CBM to KG Conversion Works
CBM (cubic meter) measures volume, while kg (kilogram) measures mass/weight. Because these are different physical quantities, there is no single universal conversion without a density or shipping factor.
The core formula is:
kg = CBM × density (kg/m³)
For logistics, carriers often use standardized volumetric factors instead of true material density. That is why air, sea, road, and courier shipments can produce different “kg” values for the same CBM.
When to Use Which Factor
1) True Material Weight
Use actual density when you want physical weight, such as for manufacturing, storage load, or engineering checks.
- Water: about 1000 kg/m³
- Wood (varies): around 400–900 kg/m³
- Steel: around 7850 kg/m³
2) Freight Chargeable Weight
Carriers may charge based on volumetric weight, not just scale weight. Common freight assumptions:
- Air freight: 1 CBM ≈ 167 kg
- Road freight (common benchmark): 1 CBM ≈ 333 kg
- Courier volumetric benchmark: 1 CBM ≈ 200 kg
- Sea freight W/M convention: 1 CBM ≈ 1000 kg (context dependent)
Always confirm your carrier’s exact policy, because formulas vary by route and provider.
Quick Reference Table
| Mode / Material | Factor (kg/m³) | Best Use |
|---|---|---|
| Air Freight | 167 | Volumetric billing estimate |
| Road Freight | 333 | Truck volumetric estimate |
| Courier | 200 | Parcel chargeable weight estimate |
| Sea Freight W/M | 1000 | LCL convention reference |
| Water | 1000 | Physical mass calculation |
| Wood (Average) | 700 | Rough mass estimate |
| Steel | 7850 | Heavy material estimate |
Example Calculations
Example A: Air Freight
You have 3.2 CBM of cargo. Using the air factor (167 kg/m³):
3.2 × 167 = 534.4 kg
Estimated chargeable weight: 534.4 kg.
Example B: Water Volume to Mass
You have a tank volume of 0.75 CBM of water:
0.75 × 1000 = 750 kg
Estimated water mass: 750 kg.
Example C: Unknown CBM, Known Dimensions
If your package is 120 cm × 80 cm × 60 cm:
- Convert to meters: 1.2 × 0.8 × 0.6
- CBM = 0.576 m³
- Air freight weight: 0.576 × 167 = 96.192 kg
Common Mistakes to Avoid
- Mixing units: Always keep dimensions in one unit system before multiplying.
- Forgetting density: CBM alone cannot convert directly to kg.
- Using wrong freight factor: Verify your carrier’s divisor/factor.
- Rounding too early: Keep more decimal places until the final result.
FAQ
Can I convert CBM to kg without density?
No. You need either material density or a freight conversion factor.
Is volumetric weight the same as actual weight?
No. Volumetric weight is a billing method based on package size. Actual weight is what the object physically weighs.
Why does sea and air conversion differ so much?
Air cargo space is more limited and expensive, so its volumetric formula is stricter. Sea freight has different cost structure and conventions.
Bottom Line
The right CBM-to-kg conversion depends on your purpose: physical mass or freight billing. Use the calculator above, choose the correct factor, and always double-check with your logistics provider for final chargeable weight.