How to use the cbm calculator
- Choose the unit your carton sizes are in: centimeters, inches, millimeters or meters.
- Enter the length, width and height of each carton size and the number of cartons. Add a weight each if you want a total weight.
- Use Add a carton size for different cartons in the same shipment.
- Optionally enter the cubic meters of the space you are comparing against and read the total CBM.
Formula
CBM of one carton = length x width x height, each side in meters
Total CBM = CBM of one carton x number of cartons, added over every carton size
Cubic feet = CBM x 35.3147 (1 CBM is 1 cubic meter)
Share of the space = total CBM / space available x 100%
Centimeters divide by 100, millimeters by 1,000 and inches multiply by 0.0254 to get meters before multiplying.
100 cartons of 50 x 40 x 30 cm
A carton that measures 50 x 40 x 30 cm is 0.5 x 0.4 x 0.3 = 0.06 CBM. A hundred of them come to 6 CBM, which is about 211.89 cubic feet.
In inches, a 20 x 16 x 12 inch carton is 0.0629 CBM, and 50 of them are 3.1463 CBM. Mixing 100 of the first cartons with two 1 meter cubes gives 6 + 2 = 8 CBM, and against 40 CBM of space that uses 20% by volume.
What CBM is used for
Freight quotes, especially for sea shipments, are often priced per cubic meter, and a CBM figure also tells you how much of a container a load might take up. Having the number before you ask for a quote makes it easier to compare offers.
The calculation is plain geometry, so the same cartons give the same CBM everywhere. How a carrier turns it into a price is up to the carrier, and it may use weight, volume or a formula that combines the two.
Limits of a volume total
The total counts only the cartons themselves. Real loads need room for gaps, pallets, strapping and the way cartons fit together, so the space used is usually more than the sum of carton volumes. Use the space available figure from your carrier and treat the percent as a guide.
To see how boxes fit on a pallet, use the boxes per pallet calculator. For volume-based shipping charges see the dimensional weight calculator, for general volumes try the volume calculator, and add shipping to your product costs with the landed cost calculator.
Assumptions and limits
- Every carton in a row has the same outside dimensions, measured in the unit you choose.
- Cartons are rectangular boxes with no gaps counted between them.
- Volume is the outside size of the carton, not the size of the contents.
- Weight, if entered, is per carton in kilograms and has no effect on volume.
Frequently asked questions
How do you calculate CBM for a carton?
Multiply length, width and height after converting each to meters. A 50 x 40 x 30 cm carton is 0.5 x 0.4 x 0.3 = 0.06 CBM.
How many cubic feet are in one CBM?
One CBM is about 35.3147 cubic feet, because a meter is about 3.28084 feet and the volume is cubed.
Can I mix carton sizes in one shipment?
Yes. Add a row for each size with its own count, and the tool adds the volumes into one total.
Does CBM tell me what shipping will cost?
No. It gives the volume only. Carriers set their own prices and may charge by weight, by volume or by a mix, so ask your carrier how a quote is built.