How to Use the CBM Calculator
Enter box dimensions (L×W×H) and select unit (cm, inches, ft, m). Enter quantity for multiple identical boxes. Get total CBM and volumetric weight for air freight quotes.
CBM Calculator Formula
CBM per box = L(m) × W(m) × H(m); Volumetric weight = CBM × 200 (air freight)Example Calculation
50cm × 40cm × 30cm box, qty 10:
CBM per box = 0.5 × 0.4 × 0.3 = 0.06 m³; Total = 0.6 m³; Vol. weight = 120 kg
Total CBM = 0.6 m³; Volumetric weight = 120 kg
What CBM Means and Why It Matters
CBM stands for cubic metre — the standard unit of volume used in shipping and freight worldwide. It measures how much space a package or shipment occupies, which is just as important as its weight when you are paying to move it. Freight companies need to know CBM because space on a truck, container, or aircraft is finite. A shipment that is light but bulky can cost more to ship than a small heavy one, and CBM is how that space is priced.
How to Calculate CBM from Centimetres
The calculation is simply length × width × height, with all three measured in the same unit and converted to metres. Most packages are measured in centimetres, so the key step is converting cm to metres by dividing by 100.
- Measure length, width, and height of the package in centimetres.
- Convert each to metres by dividing by 100 (e.g. 120 cm = 1.2 m).
- Multiply the three: CBM = L(m) × W(m) × H(m).
- Example: a 120 × 80 × 100 cm carton = 1.2 × 0.8 × 1.0 = 0.96 CBM.
For multiple identical cartons, calculate one and multiply by the quantity. The calculator above does the cm-to-metre conversion for you, so you can enter dimensions directly in centimetres.
Volumetric Weight: Why CBM Becomes Kilograms
Carriers do not just charge by actual weight — they charge by whichever is greater, actual weight or volumetric (dimensional) weight. Volumetric weight converts your CBM into an equivalent weight using a standard factor, so that a large but light shipment pays its fair share of the space it consumes. For air freight the common rule is volumetric weight (kg) = CBM × 167 (or, using the older divisor, length × width × height in cm ÷ 6000). Sea freight uses different conventions. The practical takeaway: if your goods are bulky and light, expect to be billed on volumetric weight; if they are dense and heavy, on actual weight.
Using CBM to Plan and Save
Knowing your CBM up front helps in two ways. First, it lets you compare freight quotes accurately, since carriers price by CBM or volumetric weight. Second, it helps you pack efficiently — reducing wasted space inside cartons directly lowers your CBM and therefore your cost. Even choosing slightly smaller boxes or removing excess void fill can shrink the volume you pay for. Calculate your total CBM before requesting quotes so you can check that what you are billed matches the space your shipment actually takes.
Frequently Asked Questions
What is volumetric weight in shipping?
Volumetric weight = CBM × 200 (standard for air freight). Freight is charged on the higher of actual weight vs volumetric weight. For large but light packages, volumetric weight is often higher.