How chargeable weight is worked out
Every freight mode sells a mix of weight and space, and each one has a fixed density it uses to turn space into weight. Air cargo assumes 166.67 kg per cubic metre, express couriers 200, LCL ocean 1,000, and road groupage somewhere between 250 and 333 depending on the market. Your cargo is billed on its real weight or on that volumetric weight, whichever is greater. That figure is the chargeable weight.
- Volume of the shipment = sum of length × width × height × pieces, in cubic metres.
- Volumetric weight = volume × the mode's kg per m³ (the same as cm³ ÷ the divisor).
- Chargeable weight = the greater of volumetric and gross weight, rounded the way the mode rounds: up to the next half kilogram for air and express, the next kilogram for road.
- For LCL the comparison is in revenue tonnes (W/M): cubic metres against metric tonnes, with most consolidators charging a 1 W/M minimum.
Factors by mode
| Mode | Ratio | kg per m³ | Usual rounding |
|---|---|---|---|
| Air cargo (IATA) | 1:6000 (6,000 cm³ = 1 kg) | 166.67 | Up to next 0.5 kg |
| Express and courier | 1:5000 | 200 | Up to next 0.5 kg |
| Sea LCL | W/M, 1 m³ = 1,000 kg | 1,000 | Usually to 0.01 W/M, 1 W/M minimum |
| Road groupage, Europe and UK | 1:3000 (1 m³ = 333 kg) | 333 | Up to next kg |
| Road freight, Australia | Cubic conversion 250 kg/m³ | 250 | Up to next kg |
Road factors are the least standard. Many European hauliers quote pallets or loading metres instead (see the LDM calculator), and some networks use 1:4000 or their own pallet-space rates. US LTL does not use a factor at all; it rates on density and freight class.
Worked example: three crates, five modes
Three crates, each 100 × 80 × 60 cm and 50 kg: 1.44 m³ and 150 kg gross.
- Air: 1.44 × 166.67 = 240 kg chargeable, 60 % more than the gross weight.
- Express: 1.44 × 200 = 288 kg.
- Sea LCL: 1.44 m³ against 0.15 t, so 1.44 W/M, charged on volume.
- Road, Europe: 1.44 × 333 = 479.5, billed as 480 kg.
- Road, Australia: 1.44 × 250 = 360 kg.
The crates are light for their size (about 104 kg/m³), so every mode bills on volume. For a dense load such as machine parts at 400 kg/m³, air and express bill on actual weight while LCL still bills on volume, because ocean's 1,000 kg/m³ factor is so high.
Mistakes that cost money on airway bills and LCL invoices
- Using the courier divisor on an air cargo quote. 1:5000 instead of 1:6000 overstates chargeable weight by 20 %. Ask which factor your forwarder's rate uses.
- Rounding every piece up separately. The volume is calculated for the whole shipment and the chargeable weight rounded once. A forwarder who rounds 40 pieces separately is adding weight.
- Forgetting pallet height. A pallet adds 15 cm or so to every piece and can push light cargo far into volumetric territory. For air, consider floor-loading cartons if the handling allows it.
- Tall pieces by air. Pieces over the lower-deck height or aircraft door limits move only on freighters or as main-deck cargo, often at a surcharge.
- Not checking W/M on tiny LCL shipments. Below about 1 m³ the minimum charge makes LCL poor value; compare air or express.
Questions shippers ask
What is chargeable weight in air freight?
The greater of the actual gross weight and the volumetric weight, which IATA rules calculate as cm³ ÷ 6,000 (one cubic metre = 166.67 kg). It is the weight the air freight rate per kilogram is multiplied by.
Why do couriers use 5,000 and airlines 6,000?
Express networks carry mostly small, light parcels and price space more aggressively. A 5,000 divisor makes every cubic metre count as 200 kg instead of 166.67. For parcel-specific rules by carrier, use the dimensional weight calculator.
How is LCL sea freight charged?
Per revenue tonne, W/M: the greater of the volume in cubic metres and the weight in tonnes, usually with a 1 W/M minimum. Destination charges are often quoted per W/M as well.
What volumetric factor do road carriers use?
There is no single standard. 333 kg/m³ (1:3000) is common for European and UK groupage, 250 kg/m³ is the usual cubic conversion in Australia, and some carriers use 1:4000 or pallet-space pricing. Pick "Custom" and enter your carrier's factor.
Can I enter pieces in inches and pounds?
Yes. Switch the units to in / lb; volume and chargeable weight are still shown in m³ and kg, with the pound equivalent alongside.
Sources
Rules checked: November 2026 Factors are the published standards for each mode. Your forwarder's rate sheet can use a different factor; it is the one that applies.
Rates, fees and the rule pages behind this tool are checked automatically twice a week; last check 3 November 2026.
- IATA: Cargo Tariff Coordinating Conference resolutions and TACT rules — volumetric weight 6,000 cm³ per kg
- DHL: how to calculate volumetric weight — express divisor 5,000
- Australia Post: what is cubic weight? — cubic conversion factor of 250 kg per cubic metre