If you’re someone who works with cargo shipments daily, knowing the answer to “What is CBM in containers?” is a must.
To give you an idea, CBM is short for “Cubic Meter,” and it’s one of the most important measurements in the freight and logistics industry.
So, what is CBM exactly? Why does it matter so much in container shipping? And how can you calculate it for different packages and container sizes?
Also Read: Cut Container Shipping Costs with the Best Practices
What is CBM in Containers?
To reiterate the whole question, let’s get back to “What is CBM in containers?”
CBM is the abbreviation of Cubic Meter. In international shipping, it’s used to calculate how much space your cargo takes up inside a container. One CBM equals the volume of a cube that’s 1 meter in length, width, and height.
To give you an example of how CBM works, it goes by the following illustrations:
- A simple box (with dimensions similar to the image above) equals 1 CBM.
- A smaller package, say 0.5m x 0.5m x 0.5m, equals 0.125 CBM.
CBM becomes especially important when you’re shipping goods by LCL (Less than Container Load), where your cargo shares space in a container with other shipments.
It also comes into play when calculating rates for FCL (Full Container Load) to ensure you’re maximizing space.
Importance of Knowing the CBM of Each Container
CBM plays a huge role in determining your shipping costs – sometimes even more than weight. Here’s why:
Freight Rates
Most sea freight (and even some air and rail freight) charges are based on either the CBM or the weight of your cargo, whichever is greater.
As such, this is called “chargeable weight.” For bulky but lightweight items, you’ll pay based on CBM; for heavy, compact items, weight might be the main factor.
Container Limits
Shipping containers have both weight and volume limits. If your goods are lightweight but take up a lot of space, you might fill up the container’s CBM before reaching its weight limit, and vice versa.
Logistics Planning
If you have higher CBM, it means you must spend more costs into the shipment process and space to keep up with the cargo’s overall volume.
Optimizing your shipment’s CBM can lead to significant cost savings and more efficient logistics.
Impact of CBM on Shipping Costs
Freight charges are based on either volume (CBM) or actual weight, whichever is higher. This is called the chargeable weight, which a shipping company can take into account since a container can either get full from:
- Too many heavy items (reaching the weight limit), or
- Too many bulky items (reaching the volume limit)
Let’s say you have two shipments:
- Shipment A: 0.8 CBM, 1,200 kg
- Shipment B: 1.6 CBM, 400 kg
Shipment A will be charged by weight. Shipment B, although lighter, takes up more space and is charged by volume (CBM).
In sea freight, this calculation is usually:
- 1 CBM = 1 metric ton (1,000 kg)
In air freight, it’s:
- 1 CBM = 167 kg volumetric weight
That means even if your cargo is feather-light, like pillows, if it takes up 10 CBM, your charges will reflect that large volume.
CBM Conversion to KG
If you’re trying to compare shipping charges by volume and weight, it helps to know how CBM translates to kilograms.
Sea Freight:
- Standard chargeable weight: 1 CBM = 1,000 kg
- If your cargo is over 1,000 kg per CBM, it will be charged by weight.
- If under, you pay by CBM.
Air Freight:
- Chargeable weight: 1 CBM = 167 kg
- Formula: (Length x Width x Height in cm) / 6,000 = chargeable weight in kg
Even if you’re not shipping by air, this gives you insight into how much space matters versus physical weight.
How to Calculate the CBM of Different Package Sizes
To find the CBM of any package, use this simple formula:
CBM = Length (m) × Width (m) × Height (m)
Here are a few quick examples:
A Single Box
- Dimensions: 1.0m x 0.8m x 0.6m
- CBM = 1.0 × 0.8 × 0.6 = 0.48 CBM
Multiple Boxes
- Box dimensions: 0.5m x 0.4m x 0.3m
- 20 boxes
- One box = 0.5 × 0.4 × 0.3 = 0.06 CBM
- Total CBM = 0.06 × 20 = 1.2 CBM
In Centimeters
If your dimensions are in cm, convert to meters first. Then, divide each number by 100.
- Dimensions: 80cm x 60cm x 50cm = 0.8m x 0.6m x 0.5m
- CBM = 0.8 × 0.6 × 0.5 = 0.24 CBM
Calculating Sea Shipment Cost with CBM
Once you’ve calculated CBM, estimating shipping cost becomes much easier. Here’s the basic formula:
Total Freight Cost = CBM x Rate per CBM
Let’s say the freight rate is $75 per CBM, and you’re shipping 3.6 CBM of goods. By calculating these numbers, the following is the final shipping cost:
3.6 CBM x $75 = $270 shipping cost
But remember, this is usually just the base ocean freight charge. Other charges may include:
- Origin port charges
- Destination handling fee
- Customs clearance
- Delivery to the final address
Still, CBM is the foundation of it all, meaning that you should ensure your budget can cover the charge before and after possible cost changes.
CBM for Different Container Sizes
Different shipping containers have different maximum CBM capacities. Check the following table to see the difference in CBM in each container size:
| Container Type | Internal Dimensions (m) | Max CBM (approx.) |
|---|---|---|
| 20’ Standard | 6 x 2.4 x 2.6 | 33 |
| 40’ Standard | 12 x 2.4 x 2.6 | 67 |
| 40’ High Cube | 12 x 2.4 x 2.9 | 76 |
| 45’ High Cube | 13.5 x 2.4 x 2.9 | 86 |
Note: The “usable” CBM is often slightly less than the theoretical maximum due to packaging, pallets, and the need for safe loading and unloading.
For example, a 20’ container usually fits about 26-28 CBM of cargo, even though its internal capacity is 33 CBM.
How Many Boxes Fit in a Container?
Once you know your total CBM, divide the container’s usable CBM by your shipment’s CBM per box to estimate how many boxes will fit. Online calculators make this step a breeze.
Additional Tips for Maximizing CBM Usage
To make the most of your shipping budget, try these tips:
Use Uniform Boxes
Standardizing your packaging makes it easier to stack and reduces wasted space.
Disassemble Furniture
Large furniture can take up loads of CBM. Break it down to reduce volume and improve packing density.
Avoid Overpacking
Overhanging or oddly shaped boxes might make it harder to stack and can waste space in a container.
Work with a Freight Forwarder
They’ll help you calculate CBM correctly and suggest the best way to consolidate or arrange your shipment.
Consider Shrink Wrapping or Palletizing
Depending on what you’re shipping, the use of pallets might help protect goods and improve loading/unloading, but it can also increase CBM slightly.
Also Read: RoRo and Container Shipping: When to Choose Either Option
Conclusion
By knowing the answer to the question “What is CBM in containers?” and how to calculate it, you can be sure of the actual charges you must pay before and after each cargo shipment. If you need the shipping container to be as safe as possible for the shipment, contact Tradecorp today! Experienced in leading the industry as the top container vendor, Tradecorp ensures its containers are what customers need for any business need.
