Chargeable weight is the weight an airline uses to price your shipment, and it is not always the weight on the scale. A carton of feathers and a carton of steel parts can weigh very different amounts yet take the same space on an aircraft, so airlines charge for whichever is greater, the actual weight or the space taken. Understanding that one rule explains most surprises on an air freight quote. This guide defines chargeable weight, walks through the formula, shows the density at which the rule flips, gives three worked examples with made-up cargo and lists ways to lower the weight you are billed for.
For how the figure fits into a full quote, see how air freight charges are calculated. For the mode decision, see air freight vs sea freight.
The Definition
IATA explains that air carriers can charge by volumetric weight, which it also calls dimensional weight, or by actual weight, and that whichever is higher is the amount used for pricing. To determine the volumetric figure, it says, the general rule is to divide the volume of the shipment in cubic centimetres by 6,000. IATA illustrates the idea with feathers, which are light but bulky, against steel, which is dense. Chargeable weight is simply the result of that comparison.
The Formula, Step by Step
- Measure each package as it will be flown, with its packaging, in centimetres: length, width and height.
- Multiply the three figures to get the volume in cubic centimetres.
- Divide by 6,000 to get the volumetric weight in kilograms.
- Weigh the package to get the actual weight in kilograms.
- The larger of the two numbers is the chargeable weight.
For a carton of 60 x 40 x 40 cm, the volume is 96,000 cm3, and 96,000 divided by 6,000 is 16 kg. If the carton weighs 9 kg, the chargeable weight is 16 kg. If it weighs 22 kg, the chargeable weight is 22 kg.
The Density Rule
One cubic metre is 1,000,000 cm3, and 1,000,000 divided by 6,000 is about 166.7. That gives a simple rule: cargo denser than about 167 kg per cubic metre is charged on its actual weight, and lighter cargo is charged on its volume. The table below uses made-up densities to show how far a light shipment's billed weight can move from its real weight.
| Cargo density (kg per m3) | Charged on | Chargeable weight compared with actual |
|---|---|---|
| 50 | Volume | About 3.3 times |
| 100 | Volume | About 1.7 times |
| 167 | Either | The same |
| 300 | Actual weight | The same |
| 600 | Actual weight | The same |
A shipment of very light goods, such as foam products or empty plastic containers, can therefore be billed at several times what it weighs.
Three Worked Examples
These examples use made-up cargo.
Example 1: light and bulky. Ten cartons, each 60 x 50 x 50 cm (150,000 cm3) and 8 kg. The volumetric weight is 25 kg per carton, so the chargeable weight is 250 kg for a shipment that weighs 80 kg, about 3.1 times its real weight.
Example 2: dense. Four crates, each 40 x 40 x 30 cm (48,000 cm3) and 65 kg. The volumetric weight is only 8 kg per crate, so the chargeable weight is the actual 260 kg. Better packing would not lower the bill here, since the weight itself is the limit.
Example 3: mixed pieces. Piece A is 120 x 80 x 60 cm (576,000 cm3, 96 kg volumetric) and weighs 40 kg. Piece B is 50 x 40 x 30 cm (60,000 cm3, 10 kg volumetric) and weighs 55 kg. If each piece is taken on its own, A is 96 kg and B is 55 kg, a total of 151 kg. If the whole consignment is taken together, the volumetric total is 106 kg and the actual total is 95 kg, so the chargeable weight is 106 kg. Providers do not all work this out the same way, so ask whether yours calculates per piece or for the whole consignment, because the two methods can differ by a large amount.
How to Measure Correctly
- Measure the finished package, including cartons, pallets, straps and any overhang, because the airline will measure what it receives.
- Use the longest point of each edge, not the nominal size of the product.
- Record dimensions and weights on the packing list and keep them consistent with the air waybill.
- Ask whether the airline or your forwarder rounds dimensions and weights, and in which direction.
A Simple Measuring Worksheet
Record each package on one line before you ask for a quote.
| Package | Length x width x height (cm) | Volume (cm3) | Volumetric kg | Actual kg | Chargeable kg |
|---|---|---|---|---|---|
| Carton 1 | 60 x 40 x 40 | 96,000 | 16.0 | 9.0 | 16.0 |
| Carton 2 | 50 x 35 x 35 | 61,250 | 10.2 | 9.0 | 10.2 |
| Crate 1 | 40 x 40 x 30 | 48,000 | 8.0 | 65.0 | 65.0 |
Use one row per package, add up the columns that your forwarder uses and send the worksheet with your enquiry. It saves a round of questions and makes the quote easier to check.
Pallets and Overhang: A Worked Example
A pallet of cartons is measured at its widest and tallest points. Suppose the cartons are stacked to 120 x 100 x 100 cm. The volume is 1,200,000 cm3, which is 200 kg of volumetric weight. If the load overhangs by 10 cm on one side, the measured width becomes 110 cm, the volume 1,320,000 cm3 and the volumetric weight 220 kg. A 10 cm overhang adds 20 kg, or 10%, to the chargeable weight of a pallet whose actual weight has not changed. Tidy stacking costs nothing and protects the cargo as well. For more on how to build a stable pallet, see our guide to packaging and palletizing standards.
Questions to Ask Your Forwarder About Chargeable Weight
- What divisor does the airline use, and is it the IATA general rule of 6,000?
- Is the chargeable weight worked out per piece or for the whole consignment?
- Are dimensions rounded, and in which direction?
- What happens if the airline measures something different from my declared figures?
- Does the quote assume the packing I described, and what if I change it?
- How would a different mode change the cost? See air freight from China to India and our guide to reducing air freight costs.
Mistakes to Avoid
- Pack tight. Use the smallest carton that protects the goods, and fill voids only as far as protection needs.
- Remove air. Compress soft goods where that is safe, or ship them unassembled where the product allows.
- Choose the shape. A cube wastes less space than a long, thin package.
- Avoid overhang on pallets. A pallet is measured at its widest and tallest points.
- Consolidate wisely. Combining dense and light cargo can bring the combined density up, depending on how the provider calculates it.
- Split by density. Dense items that are charged on weight can go by air while light, bulky items go by sea.
Chargeable Weight and Your Paperwork
The weight appears on the air waybill, so it needs to be right. Under Article 5 of the Montreal Convention, the air waybill includes an indication of the weight of the consignment, and under Article 10 the consignor is responsible for the correctness of the particulars and statements it inserts. IATA describes the air waybill as the contract of carriage between the shipper and the airline. A shipment whose declared figures do not match the cargo that arrives at the airport can be queried, re-measured or re-billed, so keep the packing list, invoice and air waybill consistent.
Mistakes to Avoid
- Quoting or budgeting on actual weight when the volumetric weight is higher.
- Measuring the product, not the packed cargo.
- Changing the packing after the quote without telling your forwarder.
- Ignoring density when you choose between air and sea.
- Assuming that fewer, larger packages always cost less.
Check Your Chargeable Weight With RR Brothers and Logistics
RR Brothers and Logistics can calculate the chargeable weight of your cargo before you book and suggest packing changes that lower it. See our air freight service, or send us your cargo details with the packed dimensions and weights of each piece.
Frequently Asked Questions
The weight an airline uses to price a shipment: the higher of its actual weight and its volumetric weight. IATA gives the general rule for volumetric weight as volume in cubic centimetres divided by 6,000.
Multiply length, width and height in centimetres, then divide by 6,000. A 60 x 40 x 40 cm carton is 96,000 cm3, which is 16 kg of volumetric weight.
Above about 167 kg per cubic metre, because 1,000,000 cm3 divided by 6,000 is about 167. Lighter cargo is charged on its volume.
Providers differ, and the results can differ, as the mixed-pieces example shows. Ask your forwarder which method applies to your quote.
Pack tighter, remove air, choose compact shapes, avoid pallet overhang and send light, bulky items by another mode where possible.
The air waybill includes the weight of the consignment, and the consignor is responsible for the correctness of the particulars. Keep it consistent with the packing list and invoice.
Sources
- IATA: Air cargo tariffs and rules (volumetric weight)
- Convention for the Unification of Certain Rules for International Carriage by Air (Montreal Convention 1999), full text
- IATA: e-freight and the air waybill
This article is general information, not legal, tax or customs advice. Rules, rates and procedures change; confirm current requirements with the relevant authority or a licensed customs professional before you ship. Regulatory references were checked against the official sources listed above on 25 October 2026.
Image credits: header photo by Rohit Choudhari on Unsplash; photo by GB The Green Brand on Unsplash. Used under the Unsplash License.
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