CBM Calculator
Work out the total cubic meters (CBM) of your shipment, plus cubic feet, sea and air volumetric weight, and how it fits a 20ft, 40ft, or 40ft High Cube container. Add as many line items as you need — switch between cm, in, m, and ft.
Total volume
Cubic feet
169.5
ft³
Sea weight
4,800
kg
Air weight
800
kg
Container fit · ~80% usable
Free PDF includes a watermark. Pro removes it & adds your brand.
Estimates only — container fit assumes ~80% usable volume (real packing varies with stacking and box shape). Confirm with your carrier.
How to calculate CBM
CBM is simply volume in cubic meters. Measure each item, convert to meters, and multiply:
Working in centimeters? Multiply L × W × H in cm and divide by 1,000,000. In inches, divide by 61,024. The calculator above handles every unit and adds your items together automatically. For a single box or one-off volume check, the simpler cubic meter calculator does the same math for one item.
Why CBM matters for shipping cost
Ocean LCL and air freight charge by chargeable weight — the greater of actual weight and volumetric weight. Light, bulky cargo is priced on the space it takes, so your CBM often decides the bill. Knowing CBM up front also tells you how many containers you need and whether consolidating into a full container (FCL) would be cheaper.
Frequently asked questions
How do you calculate CBM?
CBM (cubic meters) = length × width × height, with all dimensions in meters, multiplied by quantity. For centimeters, divide the result by 1,000,000. Example: a 120 × 100 × 100 cm carton is 1.2 m³; four of them total 4.8 CBM.
What is CBM in shipping?
CBM stands for cubic meter — the volume your cargo occupies. Ocean LCL and air freight are priced on volume as well as weight, so CBM is used to work out chargeable weight and how much container space you need.
How do you convert CBM to kg?
It depends on the mode. For sea/LCL, 1 CBM is treated as 1,000 kg (the revenue-ton ratio). For air freight, 1 CBM equals about 167 kg using the standard 6,000 cm³/kg volumetric factor. This calculator shows both.
How many CBM fit in a 20ft or 40ft container?
A 20ft container holds roughly 33 m³ and a 40ft about 67 m³ internally (40ft High Cube ~76 m³). Practical loading is usually around 80% of those figures once you account for pallets, stacking, and shape.
What is the CBM formula for inches?
Multiply length × width × height in inches, then divide by 61,024 to get cubic meters (there are 61,024 cubic inches in a cubic meter). This calculator does the conversion automatically — just pick the inch unit.