The CBM formula and how to calculate CBM
The CBM formula is a simple calculation – it’s the product of: the quantity of items * length * width * height.
If your shipment has different-sized items, simply repeat the formula for each size and add up the volumes.
Of course, you don’t need to use a pen and paper. Our free CBM calculator will do the heavy lifting for you – just follow these easy steps:
- Select the unit of measurement (metric or imperial)
- Type in the number of units (pallets, boxes, or crates)
- Type in the unit’s length, width, and height
- The total volume will be displayed inline
Do you need to calculate the CBM of cylindrical packages?
Check with your carrier whether they square the circle (the diameter becomes width and height) or pull out your high-school math formula and multiply the radius of the package by Pi and then again by 2 ( πr2). Then, multiply that number by the length of the package to get volume.
Want to know how to calculate CBM when shipping different sizes?
Simply run each size of an item through the calculator, write down the total volumes, and add them up.
Ready to book your shipment?
Calculate your shipment’s cubic meter volume with this free CBM calculator
Freight shipment cubic volumes are typically required to get a price quote. Use this CBM (cubic meter) calculator to easily calculate CBM and how many products fit in a shipping container.
CBM is also critical for calculating dimensional weight, chargeable weight, calculating freight class, or requesting a freight quote. This number is the basis for a lot of calculations determining what you will pay for shipping, so it’s a good idea to understand what cubic meter volume means in shipping.
What is CBM?
CBM, or in full form cubic meter, is the freight volume of the shipment for domestic and international freight. CBM measurement is calculated by multiplying the width, height, and length together of the shipment. This sounds complicated, but using a calculator can make this a quick and easy part of shipping goods.
What is CBM in shipping?
CBM is simply the volume of your shipment. On its own this may not mean much, however, this measurement is often used for other important international (courier, air, or ocean) freight calculations including:
- Dimensional weight (CBM to kg or CFT to lbs)
Dimensional (or volumetric) weight is a way to create a theoretical number representing bulky but light shipments. For example, a pallet of ping pong balls would be very light but would take up the same volume on an airplane as a pallet of weights. By calculating the dimensional weight, carriers can then determine the chargeable weight so you don’t get charged the same for a box of bricks as for a box of ping pong balls.
Chargeable weight is the greater of the dimensional/volumetric weight (aka size) or gross weight. In other words, while ocean freight pricing is fairly averse to weight and more focused on size, air freight is much more sensitive so the dimensional weight will usually play a more important role than the actual weight.
In the United States, most LTL trucking carriers have also created a theoretical number to compensate truckers for shipping oversized loads. Most products shipped by truck go by simple freight class categories determined by weight. However, CBM can also play a large role in calculating the freight class.
CBM fit for containers
Knowing your shipment volume is also required when estimating how many products will fit in a 20′ or 40-ocean shipping container. This is not a simple arithmetic formula comparing total shipment volume and container maximum capacity. It’s impossible to use every piece of space every time a container is loaded. There will always be some unused space in a container, but there are ways that carriers maximize capacity by fitting in as much as possible.
The amount of unusable space depends on the size and shapes of the items being loaded, on their packaging, and also on how the items are stowed. As a rule of thumb, the actual capacity within a container is typically a little over 80% of its maximum capacity.
With that in mind, you can use the following table to get a general estimate of how many products will fit in the four most common-sized shipping containers (20′, 40′, 40′ HC, and 45′ HC).
| Container Type | Length | Width | Height | Capacity | Maximum |
|---|---|---|---|---|---|
| 20′ | 589 cm | 234 cm | 238 cm | 26-28 CBM | 33 CBM |
| 40′ | 1200 cm | 234 cm | 238 cm | 56-58 CBM | 66 CBM |
| 40′ HC (High Cube) | 1200 cm | 234 cm | 269 cm | 60-68 CBM | 72 CBM |
| 45′ HC (High Cube) | 1251 cm | 245 cm | 269 cm | 72-78 CBM | 86 CBM |
Ocean Freight KG to CBM
For ocean freight pricing, one ton, or 1000 kg, is the equivalent of 1 CBM. This makes it fairly straightforward to calculate CBM for LCL shipments. For quick reference, here is a handy chart converting kg to CBM for ocean freight:
1 kg = 0.001 CBM
10 kg = 0.01 CBM
50 kg = 0.05 CBM
100 kg = 0.1 CBM
200 kg = 0.2 CBM
500 kg = 0.5 CBM
1000 kg = 1 CBM
Air Cargo KG to CBM
Calculating CBM for air cargo is different than for ocean freight. The standard formula used is length (cm) x width (cm) x height (cm) ÷ 6000 = volumetric weight (KG)/1 CBM ≈ 166.6666 KG.
Any calculation for air freight will use this conversion, so it’s worth noting this rule of thumb:
167 kg = 1 CBM
