CBM Shipping Calculator
Work out shipment volume in cubic meters (CBM) from carton sizes, then the chargeable W/M or weight and freight cost for sea LCL, air, road or courier.
CBM (cubic meters) is the unit freight forwarders use to price sea freight and plan container space. This calculator multiplies carton length, width and height by the number of cartons to get total CBM, then works out what you will actually be billed on: the greater of volume or weight under the W/M rule for LCL sea freight, or the chargeable weight for air, courier and road shipments.
How to use this tool
- Choose centimetres and kilograms or inches and pounds.
- Enter the outer carton dimensions, the number of cartons and the gross weight of one carton.
- Pick the shipping mode, which sets the volume-to-weight ratio.
- Enter the rate from your quote and any minimum charge to see the estimated freight cost.
Formula
CBM = length × width × height (in metres) × number of cartons
LCL chargeable W/M = max(CBM, gross weight in tonnes); other modes: chargeable weight = max(actual weight, CBM × ratio)
Centimetre dimensions divided by 1,000,000 give m³; one cubic inch is exactly 0.000016387064 m³. This model assumes air 1:6000, courier 1:5000 and road 1:3000. Air weight rounds at shipment level; each identical courier parcel rounds separately to 0.5 kg or 1 lb before summing. These are configurable-quote examples, not universal carrier rules. The entered minimum is applied to the shipment.
Example
50 cartons of 60 × 40 × 40 cm: each carton is 0.6 × 0.4 × 0.4 = 0.096 m³, so the shipment is 4.8 CBM (about 169.5 cubic feet). At 12 kg per carton it weighs 600 kg, or 0.6 tonnes. Under W/M the larger figure is 4.8, so at $65 per W/M the LCL freight comes to $312, or $6.24 per carton.
Frequently asked questions
What does W/M mean on an LCL quote?
Weight or measurement. The consolidator charges per cubic meter or per 1,000 kg, whichever gives the higher number. Most general cargo weighs less than 1,000 kg per CBM, so it is charged on volume.
Should I measure the product or the carton?
Measure the outer carton, or the whole loaded pallet if you ship palletised, including any bulge and the pallet base. Carriers re-measure cargo and bill on what they find.
When is a full container cheaper than LCL?
Compare complete LCL and FCL quotes for your lane, including origin/destination fees. There is no universal CBM break-even threshold. The table compares geometric volume only and does not prove the cartons fit.
Why is air freight charged on volume so often?
At 1:6000, any cargo lighter than about 167 kg per cubic meter is billed on its volumetric weight. Light, bulky goods such as clothing or foam packaging almost always fall in that group.
Sources
Last updated: 2026-10-30