CBM Calculator
What This Tool Does
A CBM calculator finds the volume of a shipment in cubic meters from its length, width, and height, along with related freight figures like volumetric weight and how many units fit into standard shipping containers.
You can also use this HRA Calculator.
How It’s Calculated
Volume (m³) = Length (m) × Width (m) × Height (m)
Dimensions entered in cm, mm, inches, or feet need to be converted to meters first (1 inch = 2.54 cm, 1 foot = 30.48 cm, 1 mm = 0.1 cm).
Worked example: A carton measuring 60 cm × 50 cm × 40 cm, quantity 10.
- Convert to meters: 0.6 m × 0.5 m × 0.4 m = 0.12 m³ per carton
- Total for 10 cartons: 0.12 × 10 = 1.2 m³
Volumetric weight differs by shipping mode. For air freight, the standard formula is:
Length × Width × Height (cm) ÷ 5000 = Volumetric Weight (kg)
- Per carton: (60 × 50 × 40) ÷ 5000 = 24 kg volumetric weight
For sea freight, the common industry convention treats 1 CBM as roughly equivalent to 1,000 kg for comparison purposes:
- 1.2 m³ × 1,000 = 1,200 kg volumetric equivalent
Carriers typically charge based on whichever is higher — actual weight or volumetric weight.
Edge Cases and Special Rules
- Convert units before calculating, not after: Mixing units (like length in cm and width in inches) without converting first will produce an incorrect volume.
- Air and sea use different volumetric conventions: The ÷5000 formula is standard for air freight, while sea freight typically uses the 1 CBM ≈ 1,000 kg convention — these aren’t interchangeable, and some air carriers use a ÷6000 divisor instead, so it’s worth confirming with your specific carrier.
- Chargeable weight is whichever is greater: Freight billing compares actual weight against volumetric weight and charges based on the higher figure.
- Container capacity is a theoretical maximum: Standard container volumes (based on internal dimensions) rarely translate to 100% real-world usage, since pallet shapes, stacking limits, and weight restrictions reduce practical capacity.
Using a CBM Calculator for Sea vs. Air Freight
The same base CBM figure applies to both, but how it’s used for billing differs. For sea freight (especially LCL — less than container load — shipments), CBM is compared against actual weight using the roughly 1,000 kg-per-CBM convention to determine the “revenue ton” charged. For air freight, the ÷5000 volumetric formula converts your dimensions directly into a chargeable weight in kilograms. Always confirm which convention your specific carrier or forwarder uses, since minor variations exist across different freight companies.
Who Uses This
- Exporters and importers estimating shipping costs before booking freight
- Freight forwarders and logistics coordinators planning container loads
- E-commerce sellers calculating international shipping costs
- Warehouse and supply chain managers planning storage space requirements
CBM vs. Volumetric (Chargeable) Weight
These are related but distinct concepts. CBM is a pure measurement of physical space — how much room your shipment takes up, regardless of what it weighs. Volumetric weight is a billing concept that converts that space into an equivalent weight figure, used specifically to prevent large, lightweight shipments from being charged unfairly little compared to their actual space usage. A shipment’s actual weight and its volumetric weight are often different numbers, and carriers bill based on the larger of the two.
FAQ
What does CBM stand for?
Cubic Meter — the standard unit used across sea, air, and road freight to measure shipment volume.
What is a CBM calculator used for?
Finding a shipment’s volume, its volumetric (chargeable) weight, and how many units fit into standard shipping containers.
What is volumetric weight?
A weight figure calculated from a package’s dimensions, used by carriers to charge for large but lightweight shipments fairly.
How much does 1 CBM weigh in sea freight?
Roughly 1,000 kg by common industry convention, though this can vary slightly depending on the specific carrier or forwarder.
How many CBM fit in a standard 20ft container?
Based on standard internal dimensions, a 20ft container holds roughly 31 m³ theoretically, though real-world usable capacity is typically somewhat lower.
Try It Above
Enter your package length, width, height, weight, and quantity in the CBM calculator above to get instant volume, volumetric weight, and container capacity results. Figures are estimates based on standard formulas — confirm exact billing conventions with your specific carrier or freight forwarder.