Glossary
What is CBM and volumetric weight?
CBM (cubic meter) = length × width × height of a box, in meters. Volumetric weight = CBM × a divisor set by the carrier (commonly 167 for air, 1000 for ocean) — gives a 'weight' for billing purposes when cargo is light but takes up space.
Formulas
CBM = (length cm × width cm × height cm) ÷ 1,000,000
Volumetric weight (kg):
- Air freight: CBM × 167 (or length cm × width cm × height cm ÷ 6000)
- Ocean LCL: 1 CBM ≈ 1000 kg (carrier bills max of weight or volume)
- Express courier (DHL/UPS/FedEx): CBM × 200 (or ÷ 5000)
Chargeable weight = max(actual weight, volumetric weight)
Worked example
Box: 60cm × 40cm × 30cm, 8 kg actual weight
- CBM = 60 × 40 × 30 ÷ 1,000,000 = 0.072 CBM
- Air volumetric weight = 0.072 × 167 = 12 kg
- Chargeable weight (air) = max(8, 12) = 12 kg
- Air freight at $4/kg → $48 (not $32)
Why it matters
Many small importers shipping by air get caught when their lightweight product (textiles, foam, packaging) is billed by volumetric weight 1.5-3× higher than actual. Always pre-calculate before booking.
Ocean LCL twist
Ocean carriers bill whichever is higher: weight in tonnes (1000kg) or volume in CBM. So a 0.5 CBM, 800 kg shipment is billed as 0.8 W/M (weight-measure) — the heavier wins.
Calculator
The /calculator/b2b-margin-calculator/ has built-in CBM and chargeable-weight conversion. Enter box dimensions and weight; it shows the chargeable kg the carrier will bill.
Carriers' actual divisors
| Carrier | Air divisor | Ocean basis | |---|---|---| | Standard IATA | 6000 (cm³/kg) | — | | DHL Express | 5000 | — | | UPS | 5000 | — | | FedEx | 5000 | — | | Most ocean LCL | — | 1000 kg/CBM | | Express ocean | — | 1500 kg/CBM (some lanes) |
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