CBM stands for "cubic meter" or cubic meter. Abbreviated in this way, this measure usually refers to the total number of cubic meters required to pack and ship a package. The exact method for calculating this CBM or cubication varies, depending on the form of the package.
Step
Method 1 of 4: Calculating Rectangular Block CBM
Step 1. Measure each side of the cardboard
You need to know the length, width, and height of the cardboard rectangle. Use a ruler to find the lengths of all the sides and record each value.
- CBM is a measure of volume. So, use the standard volume formula for rectangular blocks.
- Example: Calculate the CBM of a rectangular package with a length of 15 cm, a width of 10 cm, and a height of 8 cm.
Step 2. If necessary, change the size to meters
For small packages, we recommend using centimeters, inches, or feet. Before calculating CBM, convert each measure to its equivalent value in meters.
- The exact conversion formula varies depending on the units used in the initial measurement.
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Example: If the initial measurement was in centimeters, to convert to meters, divide the number of centimeters by a conversion factor of 100. Repeat this process for all three measurements. The units for length, width, and height must be the same.
- Length: 15 cm / 100 = 0.15 m
- Width: 10 cm / 100 = 0.1 m
- Height: 8 cm / 100 = 0.08 m
Step 3. Multiply the length, width, and height
According to the formula for calculating CBM, multiply the length, width, and height of the rectangular block.
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If written in abbreviated form, the formula used will look like this: CBM = P * L * T
Where P = length, L = width, and T = height
- Example: CBM = 0.15 m * 0.1 m * 0.08 m = 0.0012 cubic meter
Step 4. Record the CBM value
The product of the initial three dimensions will be the volume and CBM of one package.
Example: The package's CBM is 0.0012, indicating that this package will take up 0.0012 cubic meters of space
Method 2 of 4: Calculating Cylinder CBM
Step 1. Measure the length and radius of the cardboard
When dealing with other tubular or cylindrical packages, you need to know the height or length of the cylinder, as well as the radius of the circular side. Determine these sizes using a ruler, then note the value of each.
- Since CBM is actually a measure of volume, use the standard cylinder volume formula to calculate the CBM of a cylindrical package.
- Notice that the radius of a circle's side is half of its diameter, and that the diameter is the distance from one side of the circle to the other. To measure the radius, measure the diameter of the circle's surface and divide by two.
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Example: Calculate the CBM of a cylindrical package with a height of 64 inches and a diameter of 20 inches.
Determine the radius of this package by dividing the diameter by two: 20 inches / 2 = 10 inches
Step 2. If possible, convert this measurement to meters
For small packages, use centimeters, inches, or feet. Convert the measurement to the equivalent value in meters before calculating cubic meters.
- The conversion factor used will depend on the initial unit of measurement.
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Example: If the initial measurement was in inches, to convert to meters, divide the number of inches by a conversion factor of 39, 37. Repeat this process for both sizes.
- Height: 64 inches / 39.37 = 1.63 m
- Radius: 10 inches / 39.37 = 0.25 m
Step 3. Plug the value into the volume formula
To find the volume and CBM of a cylinder, multiply the cylinder's height by its radius. Then multiply the result of these two values by the constant pi.
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If written in abbreviated form, the formula used will look like this: CBM = H * R2 *
Where H = height, R = radius, and = constant pi 3, 14
- Example: CBM = 1.63 m * (0.25 m)2 * 3.14 = 1.63 m * 0.0625 m2 * 3.14 = 0.32 cubic meters
Step 4. Record the CBM value
The result of the calculation in the above step is the volume and CBM of one cylindrical package.
Example: Package CBM is 0.32; meaning this pack takes up 0.32 cubic meters of space
Method 3 of 4: Calculating Irregular Shape CBM
Step 1. Measure the largest distance
To calculate the CBM of an irregularly shaped package, you need to treat the package like a rectangular block package. However, since there is no consistent length, width, and height, you must identify the longest, widest, and tallest sections of the package and measure the maximum distance with a ruler. Record each of these three measurements.
- Although CBM is a measure of volume, there is no standard formula used to measure the volume of an irregularly shaped three-dimensional object. Instead of finding the exact volume, you can just calculate the approximate volume.
- Example: Calculate the CBM of an irregular-shaped package with a maximum length of 5 feet, a maximum width of 3 feet, and a maximum height of 4 feet.
Step 2. If necessary, change the size to meters
If you accidentally measure length, height, and width in centimeters, inches, or feet, you'll need to convert them to meters before calculating cubic meters from the package.
- Note that the conversion factor will vary depending on the units used for the initial measurement of the three sides of the package.
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Example: If the initial measurement in this example was in feet, to convert to meters, divide the number of feet by the conversion factor of 3.2808. Repeat this process for all three measurements.
- Length: 5 ft / 3.2808 = 1.52 m
- Width: 3 ft / 3.2808 = 0.91 m
- Height: 4 ft / 3.2808 = 1.22 m
Step 3. Multiply the length, width, and height
Treat the package as if it were a rectangle and multiply the length, width, and height values of the object.
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If written in abbreviated form, the formula used will look like this: CBM = P * L * T
Where P = length, L = width, and T = height
- Example: CBM = 1.52 m * 0.91 m * 1.22 m = 1.69 cubic meters
Step 4. Record the CBM value
After finding the result of the maximum size, you will know the volume and CBM of this irregular shaped package.
Example: The estimated CBM value for a package is 1.69. Even if it doesn't take up the entire space, it will require 1.69 cubic meters of space to pack and ship
Method 4 of 4: Calculating Total Shipping CBM
Step 1. Search CBM for each package category
If a shipment consists of multiple categories, and each category consists of a number of packages of the same size, you can calculate the total CBM without calculating the CBM of individual cartons. You will first need to find the standard carton CBM values in each category.
- Use any required CBM calculations based on the shape of the package (rectangular, cylindrical, or irregular).
- Example: The rectangular, cylindrical, and irregular packages described in the previous section of this article are all shipped in one shipment. That is, the unit CBM for the rectangular package category is 0.0012 m3, The unit CBM for cylinder package category is 0.32 m3, and the unit CBM for the irregular package category is 1.69 m3.
Step 2. Multiply each unit CBM by the number of packets
In each category, multiply the unit CBM you calculated by the number of packages in that particular category. Repeat this process until you have finished counting each category in the submissions.
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Example: There are 50 rectangular category packages, 35 cylinder category packages, and 8 irregular category packages.
- Rectangular category CBM: 0.0012 m3 * 50 = 0.06 m3
- CBM category cylinder: 0.32 m3 * 35 = 11.2 m3
- Irregular category CBM: 1.69 m3 * 8 = 13.52 m3
Step 3. Add up all CBM categories
After calculating the total CBM for each category in a single shipment, you need to add up the three totals to find the overall CBM for that shipment.
Example: Total CBM = 0.06 m3 + 11. 2 m3 + 13, 52 m3 = 24.78 m3
Step 4. Record the total CBM for your shipment
Review your work. By this time, you should already know what the total CBM is for the entire shipment. No more calculations needed.
