Cubic metres · container fill · CBM to kg
Enter carton dimensions and quantity. Get total cubic metres, cubic feet, container fill percentage and the volumetric weight an air carrier would rate it on.
Container figures are practical stuffing volumes, not the nominal internal cube — real loads rarely exceed about 85% of the nameplate figure.
CBM is cubic metres — the volume of your cargo. It is the base unit of almost every international freight quote: LCL sea freight is priced per CBM, forwarders plan container stuffing in CBM, and air freight converts CBM to a volumetric weight before rating.
The arithmetic is simple: length × width × height in metres, multiplied by the number of cartons. In inches, divide the cubic inches by 61,024. The calculator handles both.
A 20 ft container has roughly 33 m³ of internal cube and a 40 ft high cube about 76 m³. You will not load that. Cartons do not tessellate perfectly, pallets waste the space above the top layer, and doors and corner posts cost usable volume. Planning at about 85% of nominal — 28, 56 and 68 CBM — is closer to what actually goes in, and that is what this calculator uses.
There is no universal conversion, because it depends on the mode. Air freight treats 1 CBM as 166.67 kg. Ocean LCL treats it as 1000 kg. European road groupage commonly uses 333 kg. Anyone offering a single CBM-to-kg number without asking how the freight moves is guessing — see the chargeable weight calculator for the mode-specific figures.
| Container | Nominal | Practical | Payload |
|---|---|---|---|
| 20 ft GP | 33 m³ | ~28 m³ | ~28,000 kg |
| 40 ft GP | 67 m³ | ~56 m³ | ~26,500 kg |
| 40 ft HQ | 76 m³ | ~68 m³ | ~26,500 kg |
The usual break-even between LCL and a full 20 ft container sits somewhere around 13 to 15 CBM, depending on lane and season. Below that, LCL is normally cheaper; above it, the per-CBM cost of consolidation plus destination charges often exceeds a full container rate. Get both quotes when you are near the line.