Calculate shipping volume (CBM) and volumetric weight from carton sizes.
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How do you calculate CBM (cubic meters) for shipping?
CBM per carton = length × width × height in metres, and total CBM = CBM × quantity. Air-freight volumetric weight = CBM × 166.67 kg, and the chargeable weight is the greater of actual and volumetric weight. For example, a 100 × 50 × 40 cm carton is 0.2 m³; ten of them is 2 m³. Carriers charge by whichever weight is greater.
Understanding your result
Carriers charge by whichever is greater — the actual weight or the volume-based (volumetric) weight — so light, bulky goods are often charged on volume. CBM is the standard volume measure for sea and air freight.
Formula and method
CBM per carton = length × width × height (in metres). Total CBM = CBM × quantity. Air-freight volumetric weight = CBM × 166.67 kg; chargeable weight is the greater of actual and volumetric weight.
Assumptions and limitations
This computes volume and volumetric weight from the carton sizes you enter using a common air-freight divisor. Carriers use different divisors for air, sea, courier and express, and add rules for pallets, rounding and minimum charges. Always confirm the divisor and terms with your carrier. Figures are estimates for planning, not a quote.
Worked example
A 100 × 50 × 40 cm carton is 0.2 m³; ten of them is 2 m³.
How to use this tool
- Enter the carton length, width and height.
- Enter the number of cartons.
- Optionally add the weight for chargeable weight.
Common mistakes to avoid
- Mixing dimension units between cartons.
- Forgetting that light, bulky items are charged on volume.
About the CBM Calculator
The CBM Calculator finds the cubic-metre (CBM) volume of your cartons and the volumetric weight used for shipping. Enter the carton size and quantity to get the total volume and chargeable weight.
Who should use this tool
Importers, exporters, ecommerce sellers and anyone arranging freight.
Benefits
- CBM per carton and total.
- Volumetric weight for air freight.
- Chargeable weight when you add actual weight.
- Works in cm, m, mm or inches.
Practical use cases
- Estimating freight cost for a shipment.
- Comparing actual and volumetric weight.
- Planning container or pallet loading.
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Frequently asked questions
What is CBM?
Cubic metres — the volume of your shipment, found by multiplying length × width × height in metres.
What is volumetric weight?
A weight based on volume rather than mass. For air freight it is the CBM multiplied by 166.67 kg; carriers charge the greater of this and the actual weight.
Do all carriers use the same volumetric divisor?
No. The tool uses a common air-freight factor, but express couriers, sea freight and different airlines apply their own divisors and rounding rules, and some set minimum chargeable weights. Because these change the chargeable figure, check the exact divisor in your carrier's tariff before relying on the number for costing.