How to Calculate Ocean Freight CBM — Quick Overview
CBM (Cubic Metre) is the universal volume unit of ocean freight: LCL rates are quoted per CBM, container capacity is expressed in CBM, and your freight cost per unit depends on it. The formula: CBM = (Length m × Width m × Height m) × Quantity. Example: 500 cartons of 40 × 30 × 30 cm = 0.036 CBM each = 18.0 CBM total — about 63% of a 20ft container. Full walkthrough with conversions and chargeable-weight rules in our CBM formula guide.
In-Depth Guides
Each topic behind this calculator has a dedicated guide:
- CBM formula & worked examples — conversions, cubic feet, chargeable weight, common mistakes.
- Container dimensions & capacities — 20ft / 40ft / 40HC specs, usable vs geometric volume, door apertures.
- LCL vs FCL — the 15 CBM rule, the 15–28 CBM grey zone, hidden consolidation costs.
- Freight cost per unit & FBA economics — landed cost, minimum viable price, the second-container cliff.
- Weight limits & SOLAS VGM — payload by container, VGM methods, road-leg limits.
- Pallet loading — boxes per pallet, pallets per container, stack height and crush limits.
Understanding ocean freight costs: the complete picture
Getting an ocean shipment costed correctly means holding three separate numbers in your head at once: the volume your cargo occupies (CBM), the weight it carries against the container's legal payload, and the cost per unit once everything is divided out. Most costly mistakes come from optimising one and forgetting the others — packing a container full by volume only to discover it is 3 tonnes overweight, or celebrating a low per-CBM LCL rate that arrives with destination charges that make FCL the cheaper option all along. QuickCBM exists to hold all three numbers together so the trade-offs are visible before you book.
The workflow is the same whether you are an Amazon FBA seller importing a first batch, a freight coordinator planning a regular lane, or a warehouse manager building a loading plan: measure the export carton precisely, multiply out total CBM and total weight, check both against the container you intend to use, and only then look at the freight cost per unit that actually decides whether the shipment is profitable. Enter your carton dimensions, quantity, weight and freight cost above and the calculator does all four steps at once, including the container cross-check and the pallet plan.
Who this calculator is for
- E-commerce and FBA importers pricing landed cost per unit before committing to an order quantity, and checking whether an order spills into a costly second container.
- Freight coordinators and forwarders sanity-checking a client's cargo against container capacity and weight limits before quoting.
- Warehouse and logistics managers building a pallet loading plan — boxes per pallet, pallets per container, stack height — before cargo leaves the factory.
- Anyone comparing LCL and FCL at the awkward 15–28 CBM volume where the cheaper option is genuinely not obvious.