In air freight, you pay on the chargeable weight: the higher of the actual gross weight and the volumetric weight. To get the volumetric weight, multiply length × width × height in centimetres and divide by 6000. That is why a light but bulky shipment costs more than the scales suggest.
What is chargeable weight in air freight?
Chargeable weight is the weight an airline uses to invoice your shipment. The rate per kilo is multiplied by this figure, not automatically by what your goods actually weigh.
The reason is simple. An aircraft runs out of space before it runs out of payload. A bulky, light shipment takes up as much room as a heavy one. So the airline always compares two numbers: the actual gross weight and the volumetric weight. You pay on the higher one.
Air freight is already an expensive mode per kilo. Every kilo that volume adds on top of the actual weight shows up clearly on the invoice.
How do you calculate the volumetric weight of a shipment?
The standard air freight formula follows the IATA rule:
- Measure each package including pallet and packaging: length, width and height in centimetres.
- Multiply the three dimensions.
- Divide the result by 6000. That gives the volumetric weight in kilos per package.
- Add up the volumetric weights of all packages.
- Compare the total with the actual gross weight. The higher figure is the chargeable weight.
Prefer cubic metres? Then the formula works out at 167 kg per m³. That makes a handy quick check: if your shipment weighs less than 167 kg per m³, you pay on volume.
Worked example: three pallets from China
Take a shipment of 3 pallets from Shenzhen to Brussels Airport. Each pallet measures 120 × 100 × 160 cm. Total gross weight is 750 kg.
- Per pallet: 120 × 100 × 160 = 1,920,000 cm³.
- Divided by 6000: 320 kg volumetric weight per pallet.
- For 3 pallets: 960 kg volumetric weight.
- Actual weight: 750 kg.
The chargeable weight here is 960 kg. You pay for 210 kg that never show up on the scales. The quick check confirms it: 750 kg over 5.76 m³ is about 130 kg per m³, well below the 167 threshold.
Can heavy machinery be charged on volume too?
Yes. Heavy does not automatically mean the actual weight counts. Take a 3,400 kg machine packed in a crate of 320 × 240 × 275 cm.
- 320 × 240 × 275 = 21,120,000 cm³.
- Divided by 6000: 3,520 kg volumetric weight.
- Actual weight: 3,400 kg.
The chargeable weight is 3,520 kg. Volume wins again, by 120 kg.
With cargo like this, crate height is worth a closer look. If the same crate were 263 cm high instead of 275 cm, the volumetric weight would drop to 3,366 kg. The actual weight of 3,400 kg would then apply, and the difference disappears. Twelve centimetres of packaging make a measurable difference.
Height matters in another way too. In the lower deck of a passenger aircraft, the limit is around 155 to 160 cm. A 275 cm crate can therefore only fly on the main deck of a freighter such as the Boeing 747F or 777F, which takes cargo up to about 300 cm high. That limits the number of flights available.
How much does the difference cost?
Air freight rates vary widely by route, season and airline. To show the effect, we use a fictitious rate of EUR 5 per kg.
- Pallets from China: 960 kg instead of 750 kg. That is 210 kg × EUR 5 = EUR 1,050 extra.
- Machine: 3,520 kg instead of 3,400 kg. That is 120 kg × EUR 5 = EUR 600 extra.
Comparing quotes? Check which weight the rate per kilo is based on.
What information does your forwarder need for an accurate calculation?
An accurate quote starts with complete data. If something is missing, your forwarder works with an estimate and the invoice may differ later. A complete request includes:
- The number of packages.
- The dimensions per package in centimetres, including pallet and packaging.
- A description of the goods, preferably with the HS code.
- The total gross weight.
- The total volume in m³.
- The Incoterm with the place of departure. For air freight, FCA is the right choice, although FOB is still often requested in practice.
- The full delivery address.
The HS code is needed for the customs declaration on arrival. With the right code, you also know in advance which import duties apply.
Need help calculating your chargeable weight?
PLS organises air freight worldwide through a network of airlines and partners. We calculate your chargeable weight upfront and show you where savings are possible, for example in the packaging. Undecided between air and sea? We put both options side by side. Send us your shipment details and we will work out together what makes most sense.