Air freight is charged on the chargeable weight: the actual gross weight or the volumetric weight, whichever is higher. Volumetric weight in kg is length × width × height in cm ÷ 6,000 for standard air cargo. Express couriers usually divide by 5,000, which makes light, bulky parcels more expensive.
Check your own shipment: use the free volumetric weight calculator.
Key facts
- Chargeable weight = the higher of actual weight and volumetric weight.
- Air cargo (IATA standard): L × W × H (cm) ÷ 6,000 = kg.
- Express couriers: usually ÷ 5,000.
- In inches: L × W × H (in) ÷ 366 = kg at the 6,000 standard.
- Rule of thumb: 1 CBM counts as 167 kg in air cargo, or 200 kg with a 5,000 divisor.
Why do airlines charge by volume?
A plane runs out of space before it runs out of weight capacity. A box of pillows takes the same room as a box of tools but weighs far less, so airlines charge light cargo by the space it uses. Volumetric (or dimensional) weight converts that space into a weight figure.
How do I calculate chargeable weight?
- Measure each carton’s outer length, width and height in centimetres.
- Multiply them and divide by 6,000 (or 5,000 for a courier) to get volumetric weight per carton.
- Multiply by the number of cartons.
- Compare with the total actual gross weight.
- The higher figure is your chargeable weight, usually rounded up to the next 0.5 kg.
Example: 5 cartons, each 50 × 40 × 40 cm and 10 kg.
- Volumetric weight: 50 × 40 × 40 = 80,000 ÷ 6,000 = 13.33 kg per carton, so 66.7 kg in total
- Actual weight: 5 × 10 kg = 50 kg
- Chargeable weight: 67 kg (volume wins)
The same shipment by express courier: 80,000 ÷ 5,000 = 16 kg per carton, so you pay for 80 kg.
| Shipment | Actual weight | Volumetric (÷ 6,000) | Charged at |
|---|---|---|---|
| 5 cartons, 50 × 40 × 40 cm, 10 kg each | 50 kg | 66.7 kg | 67 kg |
| 2 cartons, 40 × 30 × 30 cm, 20 kg each | 40 kg | 12 kg | 40 kg |
| 1 pallet, 120 × 80 × 150 cm, 180 kg | 180 kg | 240 kg | 240 kg |
How do pallets change the calculation?
For palletised cargo, measure the whole pallet, including the base and any overhang. A pallet of light goods stacked 150 cm high can be charged at far more than its real weight. If the goods are not fragile, loose cartons sometimes come out cheaper.
When is sea freight better?
If your cargo is light and bulky, volume pushes air freight up fast. A rough check: when a shipment is more than about 2–3 CBM or 300–500 kg and is not urgent, get a sea freight quote too. See how long shipping from China takes to compare timing.
What to do next
- Get exact carton dimensions and weights from the supplier, not estimates.
- Calculate both actual and volumetric weight before you ask for quotes.
- Check which divisor your forwarder or courier uses (6,000 or 5,000).
- Ask the supplier to use the smallest carton that protects the goods.
- For larger, non-urgent shipments, compare the price with sea freight.
Common mistakes
- Quoting on actual weight only, then getting a bigger invoice
- Forgetting that couriers use 5,000, not 6,000
- Measuring the product instead of the outer carton
- Palletising light cargo when loose cartons would be cheaper
Related questions
- How do I calculate CBM for a shipment?
- FCL vs LCL: which is cheaper for my shipment?
- How is import duty calculated?
Sources: Maersk: air cargo chargeable weight. Divisors can differ by carrier, so confirm with yours. Last reviewed October 2026.