Free CBM (cubic meters) calculator
Convert any box dimensions to cubic meters (CBM) — the international shipping standard used by every freight forwarder, ocean carrier and customs form worldwide.
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Geometric estimates only — not a substitute for professional surveying or freight advice. Verify all measurements before use. How accurate is this?
Results are estimates. Consult a professional.
How the CBM calculator works
CBM — cubic meters — is the international standard for measuring cargo volume. It tells shippers, freight forwarders and warehouses exactly how much space a shipment occupies, and it drives almost every freight cost calculation. The calculator gives you two paths: enter length, width and height in meters for a direct result, or enter dimensions in feet and it converts to cubic meters using the exact NIST factor.
Worked example: a pallet of goods for ocean freight
A furniture exporter has a pallet that measures 1.2 m long, 1.0 m wide and 1.5 m high. The freight forwarder needs the CBM to quote the ocean LCL rate and to work out how many pallets fit in a 20-foot container.
CBM of common shipping containers and cargo sizes
Use this table to quickly check how your cargo volume stacks up against standard containers. Usable capacity is less than the physical interior because of wall thickness and structural members; these are the figures freight carriers actually quote.
| Container / cargo | Dimensions (m) | CBM |
|---|---|---|
| 20-ft standard container | 5.9 × 2.35 × 2.39 | 33.2 |
| 40-ft standard container | 12.03 × 2.35 × 2.39 | 67.6 |
| 40-ft high-cube container | 12.03 × 2.35 × 2.69 | 76.3 |
| Euro pallet (loaded 1.5 m high) | 1.2 × 0.8 × 1.5 | 1.44 |
| Standard pallet (loaded 1.5 m high) | 1.2 × 1.0 × 1.5 | 1.80 |
| Large box (e.g. furniture) | 2.0 × 0.6 × 1.0 | 1.20 |
| Cubic meter reference block | 1.0 × 1.0 × 1.0 | 1.00 |
Container usable-load figures are industry-standard approximations; actual usable CBM varies slightly by carrier and container age. Source: Freightos, Flexport container specifications.
When to use CBM and how to measure accurately
CBM appears in two distinct contexts: international freight (LCL ocean, air cargo) and warehouse storage. The measurement rules are the same, but the billing implications differ. Freight rates use whichever is higher — the volumetric (CBM) weight or the actual gross weight — so knowing your CBM helps you predict costs before the shipment leaves.
- Measure to the outer edge — use the outermost points of the packaging, including any protrusions, handles or corner protectors. Freight carriers measure the bounding box, not the bare product.
- Round up, not down — most carriers round each dimension up to the nearest centimeter. A box that measures 42.3 cm is billed as 43 cm. Use ceiling values in the calculator for a conservative estimate.
- Add for irregular shapes — an L-shaped sofa or an oddly packed crate is billed on its bounding rectangle, not its true shape. Use the smallest rectangle that fully contains the item.
- Check the chargeable weight — for air freight, the volumetric weight is CBM × 167 kg/m³ (IATA standard). If that exceeds the actual weight, you pay the volumetric rate.
- Use CBM for LCL planning — less-than-container-load (LCL) ocean freight is billed per CBM, usually with a 1 CBM minimum. Grouping multiple items into one shipment reduces the per-unit CBM cost.
Accuracy and limitations of CBM calculations
The geometry is exact: length times width times height gives the precise volume of a rectangular box, and the cubic-foot conversion uses the exact NIST factor (0.028316846592), not the rounded 0.0283 figure many sites use. If your dimensions are accurate, the CBM result is accurate to as many decimal places as you need.
Three things limit real-world accuracy. First, this calculator handles rectangular boxes only — cylindrical drums, irregularly shaped cargo or bundled pipes need a different approach (use the bounding-box CBM as a conservative ceiling). Second, freight carriers apply their own rounding and minimum-charge rules, so your quote may differ from this raw volume by a small margin. Third, container fill rates depend on how cargo is stacked; 33 CBM of usable container space is an industry average and individual loads may pack more or less efficiently. Treat the result as a precise planning figure for the dimensions you enter, then confirm with your freight forwarder for final billing.
CBM and freight terms defined
About this CBM calculator
This CBM calculator runs entirely in your browser — no dimensions, shipment details or personal data are sent to any server. It uses the exact NIST conversion factor for cubic feet to cubic meters and is suitable for freight quoting, warehouse planning, customs documentation and container loading estimates.
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