About the CBM Calculator
This CBM calculator converts carton dimensions into cubic meters (CBM), the unit freight forwarders use to quote sea and air shipments. Enter the length, width and height of one carton in centimetres, millimetres, metres or inches, how many cartons you are shipping and their weight, and it returns the total volume in cubic meters and cubic feet.
Importers, Amazon FBA sellers, e-commerce brands and procurement teams use CBM to compare LCL (less-than-container-load) and FCL quotes and to see how full a container will be. The calculator shows the chargeable "freight tons" for LCL (the greater of CBM or metric tons), the air-freight chargeable weight at the standard 1:6000 volumetric ratio, and how much of a 20-foot, 40-foot or 40-foot high-cube container the shipment fills.
Container capacities are typical internal volumes; real loads usually reach about 80–90% of that because of carton sizes, pallets and weight limits, so use the fill percentage as a guide rather than a loading plan.
With the default inputs, the total volume is 2.4 m³. Change any value above to recalculate instantly.
How to use the cbm calculator
- 1Choose the unit you measured the cartons in.
- 2Enter the length, width and height of one carton.
- 3Enter the number of cartons and the gross weight of each.
- 4Pick a container size to see the fill percentage.
- 5Use total CBM and the W/M or air chargeable weight when comparing freight quotes.
Formula and method
Each dimension is converted to metres (cm ÷ 100, mm ÷ 1,000, inches × 0.0254) and multiplied to get the volume of one carton in cubic meters, then multiplied by the number of cartons. One cubic meter equals about 35.315 cubic feet.
Sea LCL freight is billed per "revenue ton" (weight or measure, W/M): the greater of the volume in CBM and the weight in metric tons. Air freight bills the greater of actual weight and volumetric weight, which at the common IATA ratio of 6,000 cm³ per kg equals about 166.7 kg per cubic meter. Container fill compares total CBM with the typical internal volume of the chosen container.
- L, W, H
- Carton length, width and height
- CBM
- Cubic meters (m³)
- W/M
- Weight or measure — LCL chargeable unit
Worked examples
20 cartons of 60 × 40 × 50 cm
Each carton is 0.6 × 0.4 × 0.5 = 0.12 m³, so 20 cartons total 2.4 m³ (about 84.8 ft³). At 240 kg the LCL charge is based on 2.4 revenue tons, air freight would bill 400 kg of volumetric weight, and the load fills only about 7% of a 20-foot container.
150 cartons in inches for a 40-foot container
24 × 18 × 16 inches is 6,912 in³, or about 0.1133 m³ per carton. 150 cartons make roughly 16.99 m³, about 25% of a 40-foot container, which could hold up to about 597 such cartons by volume.
Four heavy crates shipped LCL
Four 120 × 80 × 60 cm crates total 2.304 m³ and 1,800 kg. Because 2.304 m³ is larger than 1.8 metric tons, the LCL charge is based on 2.304 W/M. For air freight the 1,800 kg actual weight exceeds the 384 kg volumetric weight, so 1,800 kg is billed.
Frequently asked questions
How do you calculate CBM?+
Multiply length × width × height of a carton in metres, then multiply by the number of cartons. For centimetres, divide the product by 1,000,000: a 50 × 40 × 30 cm box is 60,000 cm³ ÷ 1,000,000 = 0.06 m³.
How many CBM fit in a 20ft or 40ft container?+
A 20-foot standard container has roughly 33 m³ of internal space, a 40-foot about 67–68 m³ and a 40-foot high cube about 76 m³. Practical loads are usually around 25–28, 55–58 and 65–68 m³ respectively.
What does W/M mean in LCL shipping?+
Weight or measure. LCL freight is charged per revenue ton, which is whichever is greater: the volume in cubic meters or the weight in metric tons (1,000 kg). Light, bulky goods pay by volume; dense goods pay by weight.
How do I convert CBM to cubic feet?+
Multiply by about 35.315. For example, 2 m³ is roughly 70.6 ft³. To go the other way, divide cubic feet by 35.315.
How is CBM used for air freight?+
Air carriers charge the greater of actual weight and volumetric weight. With the common IATA factor of 1:6000, one cubic meter counts as about 166.7 kg, so light but bulky cargo can cost much more than its scale weight suggests.