Volume. 120 x 80 x 90 = 864,000 cubic centimetres.
Volumetric weight at 6000. 864,000 / 6000 = 144 kg.
Gross weight. 140 kg.
Chargeable weight. 144 kg, because volumetric is the greater.
Air freight · chargeable weight
Chargeable and volumetric weight
The greater of gross and volumetric, and the arithmetic that decides which one you pay. Worked through on a crate rather than described in the abstract.
- Standard divisor
- 6000
- Density break
- 166.67 kg/m³
- Express divisor, commonly
- 5000
- Hand carry ceiling
- 32 kg
What this desk is. OnBoard Courier places on board couriers: a vetted person carries the consignment in the cabin on a scheduled passenger flight and hands it over against a signature. The desk does not operate air freight, does not hold an airline contract and is not a forwarder. Air freight enquiries sent through this site are passed to a vetted forwarding partner, and the pages here are written so that you can tell which of the two you actually need.
The rule, in one line
Chargeable weight is the greater of the gross weight and the volumetric weight. That is the whole rule. Everything else is how volumetric weight is computed and which number a particular tariff plugs into the division.
Volumetric weight in air cargo is length times width times height in centimetres, divided by 6000. The 6000 is the IATA standard divisor. It is equivalent to saying that one cubic metre of air freight is charged as 166.67 kg, and it exists because an aircraft runs out of space long before it runs out of payload on most general cargo.
A worked example on a real crate
Take one crate, 120 by 80 by 90 centimetres, gross weight 140 kg.
The crate is charged as though it weighed 144 kg, and four of those kilos do not exist. Its actual density is 140 divided by 0.864 cubic metres, which is 162 kg per cubic metre, just under the 166.67 break. Two and a half centimetres off the height is enough to cross back: at 87.5 centimetres the volume is 840,000 cubic centimetres, the volumetric weight is exactly 140 kg, and the crate is charged on its gross weight instead.
Now price the same crate under a tariff that divides by 5000. 864,000 / 5000 = 172.8 kg. Nothing about the crate has changed and the chargeable weight is 20 per cent higher. If you are comparing two quotes and one is materially cheaper, check the divisor before you check the rate.
Three such pallets at 120 by 100 by 160 centimetres compute at 320 kg each, 960 kg for the shipment, whatever they weigh, unless their gross exceeds it. That number is what a forwarder is buying space for and it is the number a rate break applies to.
Where it interacts with the rate
Air freight rates step down at weight breaks, and the breaks are usually written as minimum, normal, and then bands such as 45, 100, 300, 500 and 1000 kilos. Because the steps are large, a heavier shipment can be cheaper in total than a lighter one: 290 chargeable kilos priced at the 100 kilo rate can cost more than 300 kilos priced at the 300 kilo rate. A competent forwarder checks this automatically and quotes the lower total. It is worth asking whether they did.
This is also why consolidation is cheaper per kilo. A consolidator adds your 144 chargeable kilos to other people's and buys at a break none of you would reach alone. What you give up in exchange is described on the comparison page.
When the arithmetic says use a person instead
The divisor stops being relevant when the consignment is small and dense. A 9 kg box measuring 40 by 30 by 25 centimetres has a volume of 30,000 cubic centimetres and a volumetric weight of 5 kg, so it is charged on its gross weight of 9. It is also well inside what one person carries in a cabin.
At that size the comparison is no longer between two rates. It is between a rate plus the fixed hours at each end of a cargo movement, and an airfare plus a courier. Which one wins depends entirely on the date, and on what a day late costs you. The desk that publishes this page places the second one, and will say so plainly when the first one is the right answer.
Questions people actually ask
01Which divisor applies to my shipment?
Whichever one the tariff you are quoted under uses, and you have to ask. The IATA standard for air cargo is 6000 cubic centimetres to the kilo. Express and courier tariffs commonly use 5000, which produces a higher chargeable weight for exactly the same box. A quote that does not state its divisor is not comparable with one that does.
02Do I measure the goods or the packaging?
The packaging. Chargeable weight is computed on the outside dimensions of each piece as presented, including the pallet, the crate and any overhang. This is why a well packed shipment can be cheaper than a badly packed one carrying the same goods, and why an extra ten centimetres of void on a pallet is not free.
03What is the density break?
The density at which weight and volume charge the same amount. At a divisor of 6000 it is 166.67 kg per cubic metre. Denser than that and you pay on gross weight. Lighter and you pay on volume. At a divisor of 5000 the break is 200 kg per cubic metre, so more shipments fall on the volume side.
04How is it rounded?
Air cargo is normally rounded up to the next half kilo, and many tariffs round each piece rather than the shipment. Small consignments also meet a minimum charge, below which the weight stops mattering at all. Ask for the minimum as well as the rate, because on a 4 kg shipment the minimum is the price.
05Does chargeable weight apply to a hand carry?
No. A hand carry is priced on a seat and a courier, not on a rate per kilo, so volumetric weight does not enter it. What does apply is a hard limit: 32 kg for one courier, and cabin dimensions rather than a divisor.
Where this came from
- Scheduled network, airlines and frequencies: AeroDataBox scheduled route statistics as held by this site, retrieved 2026-09-07. It is a snapshot rather than a live timetable, it includes some all cargo operators but is not a complete freighter schedule, and a carrier that is not listed may still fly the pair.
- Distances: Great circle, computed from published airport coordinates. They are shorter than a flown track and are not routing distances.
- Block times: Modelled, not measured: great circle distance times a track factor of 1.06, divided by a cruise speed of 720, 830 or 880 km/h by distance band, plus thirty minutes of taxi across the two ends. This is the same model the route calculator on this site uses. A real timetable will differ.
- Industrial sites: Public company information, checked 2026-09-07. Nothing here states or implies that any company named is a customer of OnBoard Courier or of any operator.
- Air cargo rules and definitions: The ICAO Technical Instructions and the IATA Dangerous Goods Regulations for dangerous goods, IATA Resolution 600a for the air waybill, the Montreal Convention 1999 for carrier liability, and Incoterms 2020. Where this site holds no figure of its own it says so rather than inventing one.
Who publishes this. OnBoard Courier is a hand carry placement desk in Dubai. It does not fly air freight. These pages exist because the desk is asked to rescue air freight that has run out of time often enough to have learned where the line between the two sits, and because a comparison written by somebody who sells only one of the two options is not a comparison. Found an error? Tell us and we will correct it.
Air freight, the comparison · Corridors · The Atlas · Route calculator