CBM (Cubic Metre) Calculator
Work out the cubic metres of your cargo from package dimensions and see the revenue ton.
CBM is the volume of a cargo in cubic metres: width × length × height in metres, multiplied by the number of packages. In LCL sea freight this number decides which unit the freight is charged on; in air and road part loads, the same dimensions are turned into a volumetric weight with a divisor. Entering centimetres without converting to metres is one of the most common mistakes. The calculator above does the conversion for you.
How it is calculated
Formula: CBM = width (m) × length (m) × height (m) × number of packages. If you use centimetres, divide all three sides by 100; to convert cubic centimetres to cubic metres, divide by 1,000,000. Example: 6 cartons of 120 × 80 × 90 cm. Convert to metres: 1.20 × 0.80 × 0.90 = 0.864 m³. For six packages, 0.864 × 6 = 5.184 CBM. If you multiply the same dimensions in centimetres you get 864,000; that is cubic centimetres, and used without conversion the result is a million times too large. Dimensions are the outer dimensions of the package — pallet, crate, stretch film and overhang are included.
Why you pay by the cubic metre: the revenue ton (R/T)
LCL sea freight is charged by the revenue ton (R/T). The rule is written W/M — weight or measurement: the cubic metres of the cargo are compared with its weight in tonnes, and whichever is greater is charged. At sea the equivalence is 1 CBM = 1,000 kg. For a cargo of 5.184 CBM and 2,600 kg, volume (5.184) is greater than weight (2.6), so the calculation is made on 5.184 R/T. If the same volume weighed 7,000 kg, 7 R/T would apply instead. Because the density of general commercial cargo is mostly far below 1,000 kg per cubic metre, in LCL the invoice in practice comes from volume. Most tariffs also have a minimum unit: even if the calculation falls below 1 R/T, at least 1 R/T is applied. For more, see freight and FCL and LCL.
- Comparison: cubic metres ↔ tonnes, the greater applies
- Equivalence: 1 CBM = 1,000 kg
- Most tariffs apply a minimum of 1 R/T
The pallet is volume too
For palletised cargo, height is measured from the bottom of the pallet to the highest point of the cargo. The EPAL standard euro pallet is 1200 × 800 × 144 mm, so before any cargo is placed there is already 14.4 cm of height. On a euro pallet with 130 cm of cargo stacked on it, the calculation is 1.20 × 0.80 × 1.444 = 1.386 CBM. If you calculate the same cargo from 1.30 m without counting the pallet height, you under-declare roughly 0.138 m³ per package; across ten pallets that reaches 1.38 cubic metres. A few centimetres from stretch film and protruding corners count in the same way. When the cargo is measured again at the warehouse, a volume larger than the declaration usually comes back as a correction invoice — giving the real outer dimensions from the start is cheaper.
- Euro pallet: 120 × 80 cm, pallet height 14.4 cm
- Industrial pallet: 120 × 100 cm
- Included in the measurement: pallet, crate, corner protectors, stretch film, protruding parts
Cargo that cannot be stacked: the volume you pay for grows
For non-stackable cargo, the volume you pay for can be larger than its physical volume. In a consolidation container, a package with nothing allowed on top blocks the whole column up to the ceiling, not just its own height. Some carriers therefore take the height of non-stackable packages as the container's internal height — roughly 239 cm in 20' and 40' standard containers and roughly 269 cm in a 40' HC. A package of 120 × 80 × 60 cm is 0.576 m³, but under this rule it can be charged on 1.20 × 0.80 × 2.39 = 2.294 m³. Practice varies from carrier to carrier; there is no single standard. If your cargo cannot be stacked, say so before booking, so that the difference appears in the quote from the start and not later in a correction invoice.
- For non-stackable packages, the height may be raised to the container's internal height
- The rule differs by carrier and is not universal
- Declare it before booking
Frequently asked questions
Are CBM and the revenue ton (R/T) the same thing?
No. CBM is the physical volume of the cargo; the revenue ton is the unit used in invoicing. In sea LCL, cubic metres are compared with tonnes and the greater counts as the revenue ton. For a cargo of 5.184 CBM and 2.6 tonnes the revenue ton is 5.184; if the same volume weighed 7 tonnes, the revenue ton would be 7. The CBM calculation does not change in either case; only which value is taken as the basis of charging changes.
How do I convert centimetre dimensions to cubic metres?
There are two ways: divide all three sides by 100 and multiply them in metres, or multiply in centimetres and divide the result by 1,000,000. Both give the same result. For 120 × 80 × 90 cm: 1.20 × 0.80 × 0.90 = 0.864 m³, or 864,000 ÷ 1,000,000 = 0.864 m³. A common mistake is to multiply in centimetres and forget to divide, writing a volume a million times too large.
Do I measure inside or outside the box?
Outside. The carrier charges for the space the cargo takes on the vessel or vehicle, and that is the outer dimension of the packaging. Pallet, crate, corner protectors, stretch film and protruding parts are included; height is measured from the bottom of the pallet to the highest point. If remeasurement at the warehouse gives a volume larger than declared, it becomes a correction invoice, so giving the outer dimension from the start is safer.
How do I calculate if I have packages of different sizes?
Calculate each size group separately and add them up. Multiply packages of the same size on one line, open a new line for each different size, and at the end add the CBM of all lines. Add the total gross weight in the same way and compare it with the volume. The comparison is always made at shipment level; calculating with one assumed average package understates the volume, especially in shipments that include a few large packages.
Is CBM used in air and road freight too?
Indirectly. In air and road part loads, charging is on volumetric weight instead of cubic metres, and the volumetric weight comes from the same dimensions with a divisor. The common divisor is 6000 for air and 3000 for road. In these two modes the comparison is in kilograms, at sea between cubic metres and tonnes. The logic of the calculation does not change, only the unit. See the volumetric weight calculator.