Calculators

CBM Calculator

Cubic metres for a shipment of cartons, and how many fit in a 20 ft, 40 ft or 40 ft high-cube container.

How it works

Sea freight is priced and planned in cubic metres. Convert each carton's sides to metres, multiply them and multiply by the number of cartons. For the container count, the calculator tries all six ways of standing the carton against the container's inside dimensions, keeps the orientation that fits the most, and divides the shipment by that.

CBM = length × width × height (m) × cartons
CBM
Cubic metre, 35.3 cubic feet
20 ft
About 33 CBM inside, 5.90 × 2.35 × 2.39 m
40 ft
About 67 CBM inside, 12.03 × 2.35 × 2.39 m
40 ft HC
About 76 CBM inside, 30 cm taller

Worked example

200 cartons of 60 × 40 × 40 cm, going in a 20 ft container.

  1. 1One carton: 0.60 × 0.40 × 0.40 = 0.096 CBM
  2. 2Shipment: 0.096 × 200 = 19.2 CBM
  3. 3Best fit in a 20 ft: 9 along × 5 across × 5 high = 225 cartons
  4. 4Space used: 19.2 ÷ 33.2 = 58%

19.2 CBM fits in one 20 ft container, with room for 25 more cartons.

Frequently asked questions

How many CBM fit in a 20 ft and a 40 ft container?

The internal volume is about 33 CBM for a 20 ft, 67 for a 40 ft and 76 for a 40 ft high cube. Real loads rarely use all of it. Plan on about 25–28 CBM in a 20 ft and 55–58 in a 40 ft for mixed cartons, more if your cartons divide the container's dimensions evenly.

When is LCL cheaper than a full container?

Less-than-container-load is priced per CBM, or per 1,000 kg if that is greater, plus consolidation fees at both ends. Below about 12–15 CBM it is usually cheaper than a full 20 ft; above that, a full container often costs the same or less and your goods are not handled alongside other shippers' cargo.

Why is weight sometimes the limit instead of volume?

A 20 ft container can carry around 28 tonnes, but many roads limit the loaded truck well below that. Dense goods like tiles, paper or metal fill the weight allowance with the container half empty. In that case, a 20 ft is usually the better choice than a 40 ft.

Related calculators