CBM calculator: shipping volume and container load
CBM (cubic metres) is length × width × height of a carton in metres, times the number of cartons. In the example below, 100 cartons of 60 × 40 × 40 cm make 9.6 m³ (339 cubic feet) and fill about 34.29% of a 20ft container.
CBM = length × width × height (in metres) × number of cartons · chargeable W/M = the greater of m³ and tonnes
Free, no sign-up. Pure maths: nothing you type is looked up anywhere.
Worked example
One carton of 60 × 40 × 40 cm is 0.096 m³ (3.39 cubic feet). 2,400 units at 24 a carton are 100 cartons: 9.6 m³ and 1,500 kg (3,306.9 lb).
That is 1.5 tonnes against 9.6 m³, so the shipment is billed on volume: 9.6 W/M.
A 20ft container (28 m³ usable) would be 34.29% full by volume and 6.35% by weight, and takes up to 291 of these cartons.
A 40ft container (58 m³ usable) would be 16.55% full by volume and 6.93% by weight, and takes up to 604 of these cartons.
A 40ft High Cube container (68 m³ usable) would be 14.12% full by volume and 6.99% by weight, and takes up to 708 of these cartons.
What W/M means on a freight quote
A shared container (LCL) is billed per W/M, "weight or measure": one cubic metre or one tonne (1,000 kg), whichever is greater. Most consumer products are light for their size, so the cubic metres decide; heavy, dense goods are billed on tonnes.
The W/M is what turns into the freight line of your landed cost. Freight is then one of the costs your Amazon margin has to beat, beside the fees in the FBA fee calculator.
How many cartons fit in a container
The carton counts use planning capacities, not the container's full internal cube: cartons never stack perfectly, so a 20ft container is planned at 28 m³ of usable space and a 40ft High Cube at 68 m³. A container is also limited by the weight a truck may legally carry on a US road, which is why a dense shipment can run out of weight before it runs out of space.
A sea shipment also pays the harbor maintenance fee on the goods' value, and the import duty is the same however the cartons travel.
Frequently asked questions
How do I calculate CBM?
Measure one carton's length, width and height in centimetres, multiply them and divide by 1,000,000 to get cubic metres, then multiply by the number of cartons. In inches, multiply the three sides and divide by 61,024.
What is a container loading calculator?
It works out how much of a shipping container your cartons would take up, by volume and by weight, and how many cartons fit in a 20ft, 40ft or 40ft High Cube container. This one uses conservative planning capacities and US road weight limits.
What is chargeable W/M?
The figure a shared-container (LCL) shipment is billed on: the greater of the cubic metres and the weight in tonnes. A 3 m³ shipment of 500 kg is billed on 3 W/M; a 1 m³ shipment of 2,000 kg on 2 W/M.
When is a full container cheaper than a shared one?
It depends on the volume, not the unit count. Small shipments are cheaper shared because you pay for the space you use; as the volume grows a full container's flat price wins. The landed cost calculator prices both at your quantity.
Is this the official way a forwarder measures my cargo?
No. It is an independent planning estimate. Forwarders measure the actual cartons at the warehouse, and the final cubic metres and weight on the bill can differ.
Related tools
- Landed cost calculator
Factory price plus freight, duty, MPF, HMF and import fees, per unit.
- FBA fee calculator
Size tier, fulfillment and referral fees, storage and profit per unit.
- HMF & MPF calculator
The harbor maintenance fee and merchandise processing fee on one customs entry.