About this tool
CBM means cubic metres, the standard measure of how much space cargo takes. This tool adds up the volume and weight of your packages and shows which container, if any, suits the load. Enter lengths, widths, heights, quantities and weights, and it updates as you type.
Exporters, importers, forwarders quoting and warehouse staff use it. It reads container and pallet specifications that CDUK authors and holds as editable configuration. The reference sizes are typical values, and they vary by shipping line.
It does not prove that your cargo will physically load. Door size, package shape, stacking limits and weight distribution all matter, and the tool does not model every one. Version one gives volume use, payload use and a theoretical package count. Confirm the fit with your carrier or forwarder.
How this was worked out
What the tool does with your answers, in order.
Enter each package size, quantity and gross weight, or paste rows from a spreadsheet.
Say whether packages can be stacked or turned on their side, and whether they sit on pallets.
The tool multiplies out volume per row and totals the CBM and gross weight.
It picks the smallest container that satisfies both volume at the usable fill (85 % by default) and payload.
It shows which limit binds, any warnings for door size or payload, and chargeable weight by mode.
Copy the packages, kind of packages and gross mass for the declaration.
Worked example: 120 packages, 26.4 m³, 9,850 kg
- Shipment120 packages, 26.4 m³, gross weight 9,850 kg
- Recommended1 × 20' standard (33 m³, 28,000 kg typical payload)
- Volume use 80 %, weight use 35 %
- Flagged tightthe usable limit is 85 %
- Also fits40' standard and 40' high cube
- For the declaration120 packages, kind CT, gross mass 9,850 kg
Illustrative figures that show the working, not statements about real rates or factors.
Your questions, answered.
Short answers about the Container / CBM Calculator.
How do I calculate CBM?
Multiply length by width by height in metres, then by the number of packages. For 10 cartons of 0.6 × 0.4 × 0.5 m, each is 0.12 m³, so the total is 1.2 m³. Add the volumes of every row for the shipment total. The tool converts from centimetres or inches and does the sums for you.
What is air chargeable weight?
Airlines charge on the greater of actual gross weight and volumetric weight. The tool uses a divisor of 6,000 cm³ per kg, which is about 166.67 kg per CBM. So 1.2 m³ weighing 150 kg is charged at 200 kg. Airlines can use different divisors, so confirm with your carrier.
What is LCL and when is it cheaper than a full container?
LCL is less than container load: your cargo shares a container with others and you pay by revenue tonne, the greater of CBM and tonnes. As a rule of thumb, LCL tends to suit small loads and a full container suits larger ones. The crossover varies by route and carrier, so compare quotes.
How many pallets fit in a 20-foot container?
Typically 11 Euro pallets (1.2 × 0.8 m) or 9 to 10 UK pallets (1.2 × 1.0 m) in a 20-foot standard. A 40-foot standard takes about 23 to 24 Euro pallets or 20 to 21 UK pallets. These are typical figures and vary with the container and with pallet height and load.
Why does the tool use 85 % usable fill?
Real loads rarely reach 100 % of a container's volume because of gaps between packages, uneven shapes and loading space. The tool uses 85 % by default and you can change it. A result near that limit is flagged tight. Awkward or mixed cargo may need more spare room than this.
Where do the container sizes come from?
They are typical internal dimensions, volumes and payloads for 20-foot, 40-foot, 40-foot high cube and 45-foot high cube containers. CDUK authors them as editable configuration. Actual values vary by shipping line and container, so check the specification sheet of the equipment you book.
What does this tool not cover?
It does not prove that cargo will load, produce a loading plan or check dangerous goods and weight distribution rules. Version one gives a theoretical package count for one package size. It gives road weight warnings as a guide only, and it does not quote freight. Your carrier or forwarder confirms the booking.
Data sources
- Carrier container specifications (Hapag-Lloyd equipment sheet; typical values) International · Reviewed on change; checked against carrier specification sheets
- HMRC: package type codes for CDS Data Element 6/9 United Kingdom · monitored
International · data checked 3 Oct 2026. UK government data is reused under the Open Government Licence v3.0.
Guidance only — not adviceWhat this tool is, and is not
This tool gives general guidance and indicative figures based on the information you enter and on official data available at the date shown. It is not legal, tax, customs or financial advice, it is not a ruling or a decision by any customs authority, and it does not recommend any course of action, guarantee, amount, route, supplier or service.
Customs authorities decide the classification, value, origin, charges and guarantee amounts that apply. You remain solely responsible for your declarations, guarantees, shipments and transactions, and for checking every figure against HMRC’s published guidance and the official sources before you rely on it or act on it.
Rates, rules and data can change without notice, and the results may be incomplete or inaccurate. To the fullest extent permitted by law, Customs Declarations UK accepts no liability for any loss, cost, penalty, delay or damage arising from the use of, or reliance on, this tool or its results.
