CBM Calculator
Calculate cubic meters for shipping and freight volume.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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CBM (cubic meters) is the standard unit freight forwarders and shipping companies use to quote ocean and air freight rates:
- Select your unit. Enter dimensions in centimeters, inches, feet, or meters. The calculator converts everything to cubic meters automatically.
- Enter your box dimensions. Measure the outer dimensions of your carton or package: length, width, and height.
- Enter the quantity. The number of identical boxes in your shipment. The calculator shows both per-box CBM and total shipment CBM.
Freight forwarders typically charge by CBM or chargeable weight (whichever is higher). Knowing your CBM before requesting quotes helps you understand which rate will apply and prevents billing surprises.
About CBM Calculation
CBM stands for Cubic Meter. The formula is length (cm) x width (cm) x height (cm) divided by 1,000,000. For multiple boxes, multiply by the quantity. A standard 20-foot shipping container holds approximately 25-28 CBM of cargo; a 40-foot container holds 55-58 CBM, though actual capacity depends on cargo stacking ability.
Ocean freight is typically quoted in CBM for LCL (Less than Container Load) shipments. Air freight uses chargeable weight, which compares volumetric weight (CBM x 167 kg) against actual weight, charging for whichever is greater. Knowing both helps you decide between ocean and air shipping cost effectively.
Frequently Asked Questions
What is CBM in shipping?
CBM stands for Cubic Meter and is the standard unit for measuring shipping volume in international freight. One CBM is the space occupied by a cube measuring 1 meter on each side (100cm x 100cm x 100cm). Freight rates for LCL ocean shipments are quoted per CBM, typically ranging from $15 to $50 per CBM depending on origin, destination, and market conditions. Knowing your total CBM lets you compare shipping quotes accurately.
How many CBM fit in a 20-foot container?
A standard 20-foot dry container has internal dimensions of approximately 589 cm x 234 cm x 239 cm, giving a theoretical volume of about 33 CBM. However, usable cargo capacity is typically 25-28 CBM due to floor space lost to the door structure and the need for some clearance. For planning purposes, freight forwarders commonly use 25 CBM as the practical capacity of a 20-foot container.
What is the difference between CBM and dimensional weight?
CBM measures volume in cubic meters and is used primarily for ocean freight. Dimensional weight (DIM weight) is used by air and parcel carriers to account for the space a package takes up relative to its actual weight. For air freight, carriers convert CBM to volumetric kilograms by multiplying CBM by 167 (IATA standard). They then charge for whichever is higher: actual weight or volumetric weight.
How do I calculate CBM for irregular shaped items?
For irregular items, use the outer dimensions of the smallest box that would completely contain the item (the bounding box dimensions). Freight is charged on the space the shipment occupies, not the actual shape of the item. If shipping irregularly shaped furniture or equipment, measure the maximum length, width, and height of the item in its shipping position, then calculate CBM from those maximum dimensions.