CBM Calculator
Work out the CBM of a carton or a whole shipment, in cubic metres and cubic feet, and how many cartons fit in a 20ft, 40ft or 40ft High Cube container. Mixed carton sizes are fine.
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From CBM to what really fits
Freight figures
How this was calculated
Printed from warehousecalc.com. Results are planning estimates; confirm them before you rely on them.
How to use the calculator
- Choose what you want to work out: how many cartons fit in one container, the total CBM of a shipment, or a mix of products by percentage.
- Enter the outside length, width and height of one carton. Add the carton weight if you want the payload checked. For a shipment or a mix, add one row for each product.
- Say whether all cartons are exactly this size. If they vary, enter the biggest difference and the result becomes a range.
- Choose a container, or enter your own internal size, and say whether the cartons must stay upright.
Mixed products: how many fit in the container?
When a shipment has several products, the total CBM is not enough to know if it fits. Cartons of different sizes leave different gaps. The calculator loads the container from the back in blocks, largest cartons first, and fills the gaps left beside and above them with smaller cartons. It then tells you how many cartons of each product fit in the first container, and how the rest split across further containers.
- Upright by default. Cartons stay upright and are only turned around. Choose “Any side down” only if your products allow it.
- Payload. When every product has a weight, loading stops at the container’s typical payload, so heavy goods split across containers by weight as well as space.
- Too large to fit. A product larger than the container is flagged and listed as not loaded.
The result is a planning estimate. It assumes every carton can carry the cartons stacked on it and leaves no room for handling at the doors. It does not check weight distribution or axle loads. Confirm the final plan with your forwarder or the person loading the container. For whole pallets in a container, use the Container Loading Calculator.
Mixed product container loading by percentage
Sometimes you know the mix a customer wants but not the quantity: for example, one 40ft container that is 40% product A, 40% product B and 20% product C. Choose “Mix by %” at the top of the calculator, enter the carton size and mix percentage of each product, and it estimates how many cartons of each product fit in one container at that mix. You do not enter a quantity.
- The mix is a share of cartons. 40% means 40 of every 100 cartons, not 40% of the weight or of the space.
- The percentages must add up to exactly 100%. The calculator tells you if they do not, and does not adjust them for you.
- Whole cartons only. When whole cartons cannot match the mix exactly, the result shows the requested mix and the achieved mix side by side.
- Same loading check. Each quantity is tested with the same block-loading method as the other two jobs, and stops at the payload when every product has a weight.
Example, with sample carton sizes: cartons of 40 × 30 × 25 cm, 45 × 35 × 30 cm and 50 × 40 × 35 cm, mixed 40% / 40% / 20% in a 40ft container. On volume alone about 1,508 cartons would fit. The loading check gives 1,408: 563 + 563 + 282 cartons, 63.2 m³, about 93% of the container. The achieved mix is 39.99% / 39.99% / 20.03%, as close to the request as whole cartons allow.
This is an estimate based on the container size, the carton sizes and the requested mix, not an exact loading plan. Real loads differ with the loading pattern, gaps, pallets, weight limits and how the container is actually loaded.
How to calculate CBM: the formula
CBM of one carton = length × width × height (in metres)
Total CBM = CBM of one carton × number of cartons
| You measured in | Multiply the three sides, then |
|---|---|
| Centimetres | divide by 1,000,000 |
| Millimetres | divide by 1,000,000,000 |
| Inches | divide by 61,024 |
| Metres | no conversion needed |
CBM means cubic metres (cubic meters in US spelling). Example: a 60 × 40 × 30 cm carton is 0.6 × 0.4 × 0.3 = 0.072 CBM. Five hundred of them are 36 CBM. To convert CBM to cubic feet, multiply by 35.315. To convert cubic feet to CBM, divide by 35.315 (the same as multiplying by 0.0283). Example: 36 CBM is about 1,271 cubic feet, and 1,000 cubic feet is about 28.3 CBM. The calculator above shows each result in both cubic metres and cubic feet.
The guide to CBM in shipping explains the formula in more detail, the mistakes that cause wrong figures, and why carton CBM does not tell you how many pallets you will build.
How many CBM fit in a 20ft or 40ft container?
A 20ft container has about 33 CBM of internal volume, a 40ft about 67.7 CBM and a 40ft High Cube about 76.4 CBM. These are typical internal sizes, the same ones used by the Container Loading Calculator. Sizes and payloads vary slightly between shipping lines, so check your booking if the load is tight. The guide to how many CBM fit in a container shows how much six common carton sizes really load.
| Container | Internal size (L × W × H) | Internal volume | Typical payload |
|---|---|---|---|
| 20ft Standard | 5,898 × 2,352 × 2,393 mm | 33.2 m³ (1,172 ft³) | 28,200 kg |
| 40ft Standard | 12,032 × 2,352 × 2,393 mm | 67.7 m³ (2,392 ft³) | 26,500 kg |
| 40ft High Cube | 12,032 × 2,352 × 2,698 mm | 76.4 m³ (2,696 ft³) | 26,300 kg |
A load never uses the full internal volume. How close it gets depends on how well the carton sizes fit the container, and the calculator shows the volume used.
CBM and freight charges
- Sea freight, less than container load (LCL): often charged per “weight or measure” (W/M), whichever is greater: the volume in CBM, or the weight in tonnes. A shipment of 36 CBM weighing 5,000 kg is charged as 36 W/M.
- Air freight: charged on chargeable weight, the greater of actual weight and volumetric weight. Volumetric weight is the volume in cubic centimetres divided by 6,000 for most airlines. Many couriers divide by 5,000, which gives a higher figure.
- Full containers (FCL): normally a price per container, so the fit check matters more than the CBM rate.
Rates and rules differ between forwarders and carriers. Check the basis on your quotation before comparing prices. To record the carton sizes, weights and CBM of each package for your forwarder, use the free packing list template.
Common questions about CBM
How do I calculate CBM in inches?
Multiply the length, width and height in inches, then divide by 61,024. Example: a 24 × 16 × 12 inch carton is 4,608 cubic inches, which is 4,608 ÷ 61,024 = 0.0755 CBM. You can also enter inches straight into the calculator above.
How do I convert CBM to cubic feet?
Multiply the CBM by 35.315: one cubic metre is 35.315 cubic feet. A 0.072 CBM carton is about 2.54 cubic feet, and a 20ft container’s 33.2 CBM is about 1,172 cubic feet. To go the other way, divide cubic feet by 35.315: 2,000 cubic feet is about 56.6 CBM.
How do I convert CBM to kg?
There is no direct conversion: CBM is volume and kg is weight. For freight pricing, carriers use a fixed ratio instead:
- Sea freight (LCL): 1 CBM is treated as 1,000 kg (one tonne) under the weight or measure rule.
- Air freight: with the usual divisor of 6,000, 1 CBM counts as 166.67 kg of volumetric weight.
- Couriers: with a divisor of 5,000, 1 CBM counts as 200 kg.
The Volumetric Weight Calculator works out the chargeable weight of a parcel or air shipment.
How many cartons are in 2 CBM?
Divide 2 by the CBM of one carton. Cartons of 60 × 40 × 30 cm are 0.072 CBM each, so 2 CBM is about 27 cartons by volume. How many really fit in a space depends on how the cartons stack, which is what the calculator checks.
How do I calculate the CBM of a pallet?
Measure the loaded pallet, including the pallet base and any overhang. A pallet of 1.2 × 1.0 m loaded to 1.5 m high is 1.2 × 1.0 × 1.5 = 1.8 CBM. To work out how many cartons go on the pallet, use the Pallet Calculator.
Results are planning estimates. See the methodology for how the tools work and their limits.