CBM Calculator
This CBM calculator finds the cubic meters of a shipment from the carton size and quantity. Enter the dimensions in centimeters, millimeters, inches, feet, or meters and the number of cartons, and the CBM calculator returns the total CBM plus a CBM to CFT conversion, so you have the volume freight forwarders quote on.
Results
The CBM Calculator is part of our Shipping collection. Browse more shipping to size, convert, and check your work alongside this tool.
What the CBM calculator does
The CBM calculator measures the volume of a shipment in cubic meters, the unit freight forwarders quote on. Ocean and air freight price by volume as much as by weight, so this cubic meter calculator turns your carton size and quantity into the CBM figure a forwarder needs. It also runs a CBM to CFT conversion, since some carriers quote cubic feet, making it a complete calculator for CBM whichever unit your quote uses.
CBM formula and CBM to CFT conversion
The CBM calculator multiplies the three dimensions for one carton, then by the quantity:
With dimensions in meters the result is cubic meters directly. For the CBM to CFT conversion the calculator multiplies CBM by 35.31, and to convert CFT to CBM it divides by 35.31:
CBM formula in cm and inches
When the carton is measured in centimeters or inches, divide the product of the three sides by the number of cubic units in one cubic meter:
For millimeters divide by 1,000,000,000, and for feet divide by 35.31. The calculator does the conversion for you once you pick the unit.
CBM calculator example
Ten cartons each 60 by 40 by 50 cm:
Running the CBM to CFT conversion, that cubic meter calculation is about 42.4 cubic feet. The same job in inches: ten cartons of 24 × 16 × 20 in give 7,680 cubic inches each, and 7,680 × 10 ÷ 61,023.7 = 1.2585 CBM.
How to use the CBM calculator in cm or inches
Choose the unit your carton is measured in: centimeters, millimeters, inches, feet, or meters. Enter the carton length, width, and height, then the number of cartons. The CBM calculator converts the dimensions to meters and returns the volume per carton and the total CBM for the shipment. It also shows cubic feet through the built-in CBM to CFT converter, so a cubic feet to CBM converter check is one glance away.
Reading the CBM calculator result
Compare the total CBM to container capacity to plan a load. A 20-foot container holds around 28 to 30 usable CBM and a 40-foot roughly double. When your cubic meter calculation approaches those limits, you know how many shipments fit a container. Freight forwarders also weigh CBM against weight to set the billing basis, so the CBM to CFT converter helps when a carrier quotes in cubic feet instead.
When to use the CBM calculator
- Getting an ocean or air freight quote with a CBM calculator for shipping
- Running a CBM to CFT conversion for a carrier that quotes cubic feet
- Planning how many cartons fit a container by cubic meters
- Understanding the meaning of CBM in shipping for an invoice
Common CBM calculation mistakes
- Mixing units. Measure all three sides in the same unit and pick that unit in the calculator.
- Forgetting the CBM to CFT conversion. A carrier quoting cubic feet needs the converted figure.
- Ignoring wasted space. Cartons rarely fill a container perfectly, so leave a margin below the CBM limit.
Tips for accurate CBM results
- Measure the outer carton, rounding up to the nearest centimeter or quarter inch.
- Use the CBM to CFT converter when a carrier quotes in cubic feet.
- Compare CBM against weight to anticipate the billing basis.
CBM and the volume-versus-weight decision
The CBM calculator sits at the heart of how freight is priced. Carriers compare the CBM of a shipment against its weight using a conversion ratio, then bill on whichever is greater. For ocean freight the rough rule is one CBM against one tonne; for air freight the volume counts far more heavily. This is why a cubic meter calculation matters as much as the scale reading, and why the meaning of CBM in shipping comes up on almost every quote. Knowing your CBM in advance, and the CBM to CFT conversion for carriers that quote cubic feet, lets you plan packaging that keeps the billed volume down.
From CBM to container planning
Once the CBM calculator gives your total volume, container planning becomes arithmetic. Knowing a 20-foot box offers around 28 usable CBM, you can see immediately whether your shipment fills one, needs a 40-foot, or should share a consolidated load. The cubic meter calculation also guides how to split orders across containers economically. Running the CBM calculator for shipping early, before cartons are even packed, is what lets exporters quote and book freight with confidence rather than paying for wasted space.
Reference Table
| Container | Usable CBM |
|---|---|
| 20 ft | ~28–30 |
| 40 ft | ~56–60 |
| 40 ft HC | ~68 |
CBM Calculator FAQ
How do I calculate CBM?
Multiply carton length by width by height in meters, then by the number of cartons. The CBM calculator does this cubic meter calculation and shows the total in CBM and cubic feet.
How do I convert CBM to CFT?
Multiply CBM by 35.31 to get cubic feet. The CBM calculator includes a CBM to CFT converter, and to convert CFT to CBM it divides by 35.31.
What is the meaning of CBM in shipping?
CBM stands for cubic meter, the volume a shipment occupies. Freight is priced on CBM as much as weight, which is why a CBM calculator for shipping is essential for accurate quotes.
How many CBM fit in a container?
A 20-foot container holds around 28 to 30 usable CBM and a 40-foot about double. Compare your cubic meter calculation to these to plan the load.