WorldCalcs

CBM Calculator (Cubic Meters for Shipping)

Enter the carton dimensions in centimetres and the number of cartons to get the shipping volume in cubic metres and cubic feet.

Reviewed by the WorldCalcs team · Methodology · Last reviewed: September 2026

Quick answer

CBM = length × width × height in centimeters ÷ 1,000,000, times the number of identical cartons. Example: a 40 × 30 × 50 cm box is 0.06 CBM, so 100 boxes are 6 CBM (≈ 211.89 cubic feet).

Total volume

6CBM (m³)

Cubic feet
211.89 ft³
Per carton
0.06 CBM

CBM = length × width × height (cm) ÷ 1,000,000 × quantity

What CBM means on a freight quote

CBM is short for cubic metre — the volume your goods occupy. Sea freight is usually quoted per CBM, so the first thing a forwarder asks for is the dimensions and the number of cartons.

The arithmetic is simple because a cubic metre is 100 × 100 × 100 centimetres, which is 1,000,000 cubic centimetres. Multiply the three sides in centimetres, divide by a million, and multiply by the number of cartons.

Turning CBM into container space

Practical loading capacity is roughly 26–28 CBM in a 20 ft container and 56–58 CBM in a 40 ft container. The theoretical internal volumes are higher — around 33 and 67 CBM — but no real shipment uses all of it.

The gap is the space lost to pallets, to box dimensions that do not divide evenly into the container, and to stacking limits on what can go on top of what. Plan with the practical figures, not the theoretical ones.

Worked example

Say you are shipping 100 identical cartons, each 40 × 30 × 50 cm.

One carton is 40 × 30 × 50 = 60,000 cubic centimetres. Divide by 1,000,000 to get cubic metres: 0.06 CBM per carton.

For the full shipment, multiply by the quantity: 0.06 × 100 = 6 CBM. In imperial units that is 6 × 35.3146667 ≈ 211.89 cubic feet.

All calculations happen in your browser. Nothing is sent, stored, or tracked.

Results are estimates and may contain errors — for general information only, not professional advice. Always verify before relying on them. Disclaimer

How to use

Measure the carton in centimetres — length, width and height on the outside of the box, since that is the space it takes up on the truck or in the container.

Enter the number of identical cartons. Cartons of different sizes have to be calculated separately and added together.

Read the total volume in CBM (cubic metres), with the cubic feet equivalent and the volume of a single carton shown underneath.

Frequently asked questions

What is CBM used for?+

Freight pricing and container planning. Sea freight is usually quoted per CBM, so the volume of your cartons is what a forwarder needs before quoting.

How many CBM fit in a container?+

Practical loading capacity is roughly 26–28 CBM in a 20 ft container and 56–58 CBM in a 40 ft container. The theoretical volumes are about 33 and 67 CBM, but you can never use all of it — pallets, box shapes and stacking limits get in the way.

Can I enter inches instead of centimetres?+

Convert first — see the length converter. One inch is 2.54 cm, so a 16 × 12 × 20 inch carton is 40.64 × 30.48 × 50.8 cm.

What is the difference between CBM and volumetric weight?+

CBM is the raw volume. Volumetric weight converts that volume into a billable weight using a divisor set by the carrier, so the carrier can charge bulky-but-light freight by the space it occupies.

How do I measure an irregular shape?+

Use the longest, widest and highest points. Carriers measure the box that would enclose the item, so anything sticking out counts towards the dimensions.

References

  • Standard sea freight practice — CBM as the basis for LCL pricing and container planning (see, for example, the Freightos CBM guide, freightos.com).

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