Using this CBM calculator
CBM — cubic meters — is the standard volume unit for freight quotes, warehouse planning, and container loading. Enter the length, width, and height of a box or pallet, choose your unit (centimeters, inches, meters, or feet), set an optional quantity, and click Calculate. Results show total CBM, cubic feet, and volumetric weight used by many carriers for air and express shipments.
- Pick a unit — cm (default), in, m, or feet. Feet mode adds optional inch fields for each dimension.
- Enter dimensions — length, width, and height of one unit (box, crate, or pallet).
- Set quantity — how many identical units you are shipping (default 1).
- Optional weight — enter actual weight per unit in kg or lb to compare against volumetric weight.
- Read results — CBM, cubic feet, volumetric weight, and chargeable weight when actual weight is provided.
How to calculate CBM
First convert each dimension to meters. Then multiply length × width × height to get the volume of one unit in cubic meters. Multiply by quantity for the total shipment volume.
Quick reference conversions:
- Centimeters to meters: divide by 100 (100 cm = 1 m)
- Inches to meters: multiply by 0.0254 (exact definition)
- Feet and inches to meters: convert to total feet, then multiply by 0.3048
Example: a carton measuring 100 cm × 50 cm × 40 cm has volume 0.1 × 0.5 × 0.4 = 0.2 CBM. Need other unit conversions? Use our Conversion Calculator.
What is volumetric weight?
Light but bulky cargo takes up space in a truck, plane, or container. Carriers therefore charge by the greater of actual weight and volumetric (dimensional) weight. For air freight, a common divisor is 6000 when dimensions are in centimeters:
For the same 100 × 50 × 40 cm box, volumetric weight = (100 × 50 × 40) / 6000 = 33.33 kg. If the box actually weighs 20 kg, the carrier bills 33.33 kg. Divisors vary by mode and carrier (5000 for some express services, 4000 for road freight in some regions) — confirm with your forwarder.
Cubic feet from CBM
US warehouse and trucking quotes often use cubic feet. Multiply CBM by 35.3147 to convert:
0.2 CBM × 35.3147 ≈ 7.06 ft³
The calculator outputs both units automatically so you can compare ocean, air, and domestic quotes without re-entering dimensions.
20ft and 40ft container capacities
Container nominal volume is larger than usable cargo space because of door height, packaging gaps, and irregular shapes. Practical planning figures:
| Container type | Internal length (approx.) | Usable CBM (planning) |
|---|---|---|
| 20ft standard | 5.9 m | 28–33 CBM |
| 40ft standard | 12.0 m | 58–67 CBM |
| 40ft high cube | 12.0 m (taller) | 68–76 CBM |
Stack identical cartons with known CBM to estimate how many fit. Leave margin for dunnage, pallets, and loading access. For mixed cargo, sum each SKU’s CBM from this tool.
Trailer and LTL volume
A typical 53 ft dry van trailer offers roughly 100–110 CBM of usable space depending on deck height and pallet configuration — less than a 40ft high-cube ocean container in linear length but similar for palletized freight. Less-than-truckload (LTL) carriers also apply dimensional weight rules; knowing CBM upfront helps compare LTL vs full-truckload (FTL) options.
When CBM matters
| Use case | Why CBM helps |
|---|---|
| Ocean FCL/LCL quotes | Freight rates are quoted per CBM or per container; accurate volume avoids re-bills. |
| Air & express | Volumetric weight often exceeds actual weight for bulky goods. |
| Warehousing | Storage fees may be per pallet position or per cubic meter stored. |
| Import duty estimates | Some tariffs reference volume or combine weight and volume tests. |
| Project planning | Sum CBM of materials before ordering containers or scheduling deliveries. |
For date-based delivery windows or lead-time planning alongside volume, pair this tool with the Age Calculator to count days between order and ship dates. For length and weight unit conversions outside CBM, use the Conversion Calculator.
Examples and use cases
Case study: LCL ocean freight
An importer ships 24 cartons at 0.2 CBM each (100 × 50 × 40 cm) for a total of 4.8 CBM. The forwarder quotes $85 per CBM for LCL — about $408 freight vs a full 20ft container minimum. Summing CBM per SKU avoids over-ordering container space.
Real-world use cases
- Air vs ocean: A lightweight electronics shipment weighs 80 kg but volumetric weight is 120 kg — the carrier bills the higher figure.
- Warehouse storage: A 3PL charges per CBM stored; this tool totals palletized inventory before signing a contract.
- E-commerce packaging: A seller right-sizes cartons to reduce CBM and cut dimensional shipping surcharges.
Accuracy and limitations
Results assume rectangular boxes with uniform dimensions. Odd shapes, void fill, and non-stackable items need extra allowance. Carrier divisors, rounding rules, and minimum charges differ — treat volumetric weight as an estimate until your forwarder confirms. This tool runs in your browser for planning and education; verify critical shipments with your logistics provider.