How to Calculate CBM: LCL vs FCL from China

CBM means cubic metres. Multiply each carton's length × width × height in metres, then multiply by the number of cartons. Sea LCL (less than container load) is usually charged on whichever is greater, cubic metres or tonnes, while FCL (full container load) is a flat price for the whole container whatever is inside.

This guide is for buyers anywhere in the world shipping goods from China by sea. Last updated: November 2026.

How do you calculate CBM?

CBM = length (m) × width (m) × height (m) × number of cartons.

Example: cartons measuring 60 × 40 × 50 cm, weighing 15 kg each, 50 cartons in total.

One carton: 0.6 × 0.4 × 0.5 = 0.12 m³.
The shipment: 0.12 × 50 = 6 m³.
Total weight: 15 × 50 = 750 kg, or 0.75 tonnes.

Use the outer carton dimensions from the supplier's packing list, not the product size.

How is LCL freight charged?

Most LCL ocean freight is charged on the higher of 1 cubic metre or 1,000 kg, known as weight or measure (W/M). In the example, 6 m³ beats 0.75 tonnes, so the shipment is charged on 6 units of volume. Dense goods such as metal parts can flip that, making weight the deciding figure. Minimum charges and local fees vary by forwarder, so always ask for an all-in quote.

Container sizes at a glance

Nominal figures for general purpose containers, from Hapag-Lloyd's container specification:

Container	Inside length (m)	Width (m)	Height (m)	Capacity (m³)	Max payload (kg)
20ft	5.90	2.35	2.39	33.2	30,200
40ft	12.03	2.35	2.40	67.7	28,800
40ft High Cube	12.03	2.34	2.70	76.3	28,650

You will not load the full capacity: gaps between cartons and space above the stack reduce usable volume. Ask your forwarder for a load plan.

LCL or FCL?

Factor	LCL	FCL
Volume	Small to medium	Close to a container's capacity
Pricing	Per m³ or tonne	Flat rate per container
Transit	Usually longer, with consolidation and deconsolidation at warehouses	Factory to port directly
Handling	Loaded and unloaded more than once	Sealed at the factory, opened at destination

Rule of thumb: get two quotes for the same cargo, one LCL and one 20ft FCL, and compare the full door-to-door cost. The larger the volume, the closer FCL comes to being the cheaper option.

Common mistakes

Using product dimensions instead of carton dimensions.
Forgetting pallets, which add height and footprint.
Mixing centimetres and metres.
Ignoring weight for heavy goods, which can set the price or hit the container's payload limit first.