CBM for Furniture Exports: From Cartons to Container Loads
How to calculate cubic metres for carton lots, why 390 kg/m³ decides cube-out versus weigh-out, and how to plan container counts.
CBM is the language of freight
Ocean freight quotes, warehouse storage and courier surcharges all speak in cubic metres. CBM is length × width × height in metres: the 60 × 40 × 40 cm carton that packs most flat-pack furniture is 0.096 m³, and a hundred of them is 9.6 CBM. Mixed-size lots just add up line by line, which is exactly what CBM does - and the gross weight per carton you enter there unlocks the check that matters in the next section.
How much fits in a container
Nominal volumes mislead: a 40 HC claims 76.4 m³ but loads roughly 62-68 m³ of real cartons after wall curvature, pallet footprint and loading losses; a 20 GP claims 33.2 m³ and takes 25-28. A 40 GP sits between at 54-58. Freight forwarders plan with these usable numbers, not the brochure ones, and container presets in our Container loading calculator carry the same figures with per-carrier payload overrides.
Cube-out versus weigh-out
Which limit bites first depends on density. Divide payload by usable volume and a 40 HC balances at about 390 kg/m³ (26,500 kg / 68 m³); a 20 GP balances near 1010. Furniture and mattresses, far below the line, are cube-out cargo: they fill the box long before they threaten the crane. Dense hardwood products - worktops, parquet blocks, tool handles - hit the payload with space to spare. CBM prints the verdict from the lot density you ship.
Planning the shipment
Work the numbers in order: carton CBM × count gives the lot, lot CBM ÷ usable container volume gives an optimistic container count, then correct for stackability and loading efficiency - 90-95% packing factor is realistic for uniform cartons, less with mixed sizes. A 9.6 CBM lot of the 0.096 m³ cartons at 104 kg/m³ divides into a 40 HC seventeen times over by volume and never by weight: one container, half full, cube-out as expected.
Where furniture exporters lose money
Three classic leaks: cartons designed without the container in mind (odd heights that stack to wasted air), density just above the balance point (paying for space the weight forbids), and forgetting that moisture matters in transit - a container is not a kiln, and green timber cargo can arrive over its payload after absorbing humidity, which Green log weight helps you anticipate. CBM arithmetic is free; getting it wrong after the container doors close is not.