CBM Calculator Widget
Embed a CBM calculator on a freight-forwarding, sourcing or import page. Users enter carton dimensions, the number of cartons and the weight per carton, and see the shipment volume in m³ and ft³, the total weight, and what share of a 20', 40' or 40' high cube container it would fill.
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<iframe src="https://a2z.tools/embed/w/cbm-calculator" title="CBM Calculator by A2Z Tools" width="100%" height="780" style="border:0;width:100%" loading="lazy" allow="clipboard-write"></iframe>
A plain iframe. Works everywhere, including site builders that strip scripts. Adjust height if your content needs more room.
<div data-a2z-widget="cbm-calculator" data-height="780"></div> <script async src="https://a2z.tools/embed.js"></script>
Adds a small script (what it does) that sizes the widget to fit its content, loads it lazily and keeps it isolated from your page's CSS.
Works with
How it works
CBM simply means cubic metres. The widget converts each carton dimension to metres (centimetres / 100, or inches x 0.0254), multiplies length x width x height for the volume of one carton and multiplies by the carton count. Cubic feet use the exact foot of 0.3048 m, so 1 m³ = 35.315 ft³. With a weight per carton it also gives the total gross weight and the volume ratio in kg per m³, which forwarders use to decide whether a less-than-container-load shipment will be charged by weight or by volume. Container fill compares the total with the load capacities Ocean Network Express publishes for its standard boxes: 33.1 m³ for a 20' dry, 67.6 m³ for a 40' dry and 76.2 m³ for a 40' high cube. Above 100% it shows how many containers the volume would need. 500 cartons of 50 x 40 x 30 cm make 30 m³ - 90.6% of a 20' box by volume, more than cartons usually achieve in practice.
Calculation method
- CBM per carton = length(m) x width(m) x height(m); cm / 100 = m; in x 0.0254 = m
- Total CBM = CBM per carton x number of cartons
- Cubic feet = CBM x 35.3147 (1 ft = 0.3048 m)
- Gross weight = weight per carton x cartons; volume ratio = kg / m³
- Fill % = total CBM / container capacity (20' dry 33.1 m³, 40' dry 67.6 m³, 40' high cube 76.2 m³)
Worked examples
Export cartons
Inputs: 50 x 40 x 30 cm, 500 cartons, 15 kg each
Result: 30 m³; 1,059.4 ft³; 7,500 kg; 20' dry 90.6% full; 40' high cube 39.4% full
0.06 m³ per carton.
Imperial cartons
Inputs: 24 x 16 x 16 in, 250 cartons, 25 lb each
Result: 25.171 m³; 888.9 ft³; 6,250 lb; 20' dry 76% full
Each carton is 6,144 in³ = 0.1007 m³.
Limitations
- Container fill is by volume only and assumes perfect packing; real loads are lower and must also respect payload limits.
- Container capacities are one carrier's reference figures; individual containers vary slightly.
- Pallets, bulges and irregular shapes are not added - measure the outer dimensions of the packed unit.
Where publishers use it
- A freight forwarder's LCL quote form asking for total CBM
- Alibaba and factory-sourcing guides explaining how many cartons fit a container
- Amazon FBA sellers planning an ocean shipment from Asia
- Furniture and building-materials importers estimating container count
- Moving companies quoting international household shipments by volume
Questions
How do I calculate CBM?
Multiply length x width x height in metres, then by the number of cartons. A 50 x 40 x 30 cm carton is 0.5 x 0.4 x 0.3 = 0.06 m³; 500 of them are 30 m³.
How many CBM fit in a 20 ft container?
Ocean Network Express lists a load capacity of 33.1 m³ for its 20' dry container (inside 5,898 x 2,350 x 2,390 mm). Real carton loads come in well below that because cartons do not fill every gap, so treat a high fill percentage as a warning to check a load plan.
What is the difference between a 40' and a 40' high cube?
The same floor (12,032 x 2,350 mm inside) but about 30 cm more height: 2,695 mm against 2,390 mm, giving 76.2 m³ instead of 67.6 m³ in ONE's specifications.
Should I measure the carton or the pallet?
Measure what the consolidator will actually receive. If cartons arrive shrink-wrapped on a skid, enter the palletised unit with its overhang and the pallet height; loose cartons are measured individually. Bulging or damaged boxes measure larger at the receiving warehouse, which then bills the bigger figure.
How do I convert CBM to cubic feet?
Multiply by 35.3147. 30 m³ is 1,059.4 ft³; going the other way, divide cubic feet by 35.3147.
Why does the volume ratio matter for LCL freight?
Less-than-container-load ocean freight is commonly charged per 'revenue ton' - the greater of the weight in tonnes and the volume in m³ - so a shipment heavier than 1,000 kg per m³ pays by weight. Check your forwarder's tariff for the exact rule.
Can I enter inches and pounds?
Yes. Switch to Imperial: 24 x 16 x 16 in cartons are 0.1007 m³ each, and 250 of them make 25.17 m³ (888.9 ft³).
Sources
- Container Information - Dry containers - Ocean Network Express (ONE) . Dry 20 ft: inside 5,898 x 2,350 x 2,390 mm, 33.1 m³; dry 40 ft: 12,032 x 2,350 x 2,390 mm, 67.6 m³; dry 40 ft high cube: 12,032 x 2,350 x 2,695 mm, 76.2 m³ (reference values; individual containers vary). Checked 2026-10-01.
Cite or recommend this tool
If you reference this tool in an article, course or documentation, these formats are ready to copy. They are optional - nothing is added to your site unless you paste it.
A2Z Tools CBM Calculator https://a2z.tools/embed/cbm-calculator
<a href="https://a2z.tools/embed/cbm-calculator">A2Z Tools CBM Calculator</a>
[A2Z Tools CBM Calculator](https://a2z.tools/embed/cbm-calculator)
CBM Calculator by A2Z Tools - https://a2z.tools/embed/cbm-calculator
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