How to Calculate Chargeable Weight for Air Freight
Carriers don't simply bill the weight on the scale. Here is how chargeable weight works, the formula by transport mode, and a worked example you can follow.
Chargeable weight is the greater of the actual weight and the volumetric weight. For air freight, find the volumetric weight as length × width × height in cm ÷ 6000 (kg), compare it with the weight on the scale, and bill the larger of the two. A 60 × 40 × 50 cm carton weighing 18 kg has a volumetric weight of 20 kg, so it is charged as 20 kg.
What chargeable weight is
Carriers charge for the resource your cargo consumes — sometimes that is weight, sometimes it is space. To keep pricing fair, they bill the greater of two numbers: your actual weight (what the scale reads) and your volumetric weight (the weight your shipment's volume represents). The larger figure is the chargeable weight, and that is what your rate is multiplied by.
Dense cargo (machinery, liquids) is usually governed by its actual weight. Light, bulky cargo (cushions, lampshades, empty enclosures) is governed by its volumetric weight, because it takes up far more space than its mass would suggest.
The air freight formula
The two steps are:
volumetric weight (kg) = L × W × H (cm) ÷ 6000
chargeable weight = max(actual weight, volumetric weight)
The 6000 is the IATA dimensional factor for air cargo: one cubic meter of space is treated as 167 kg (1,000,000 cm³ ÷ 6000). Some carriers and express services use a different divisor — see the table below.
Worked example
A single carton, 60 × 40 × 50 cm, with an actual weight of 18 kg, going by air:
| Step | Calculation | Result |
|---|---|---|
| Volume in cm³ | 60 × 40 × 50 | 120,000 cm³ |
| Volumetric weight | 120,000 ÷ 6000 | 20 kg |
| Actual weight | on the scale | 18 kg |
| Chargeable weight | max(18, 20) | 20 kg |
The volumetric weight (20 kg) beats the actual weight (18 kg), so the shipment is billed as 20 kg — rounded up to the next 0.5 kg if your carrier does that.
Divisors by transport mode
The divisor changes the volumetric weight, so always use the right one for your mode and carrier:
| Mode / service | Divisor | Per CBM |
|---|---|---|
| Air freight (IATA standard) | 6000 | ≈ 167 kg |
| Courier / express (common) | 5000 | = 200 kg |
| Road freight (typical) | 3000–4000 | 250–333 kg |
| LCL sea freight | revenue ton | 1 CBM = 1,000 kg |
Volumetric weight vs CBM
Volumetric weight and CBM measure the same thing — your shipment's size — but express it differently. CBM is the raw volume in cubic meters; volumetric weight converts that volume into kilograms using the divisor. If you already know your CBM, multiply it by 167 for the air volumetric weight. For the difference in detail, read volumetric weight vs actual weight and what CBM means in shipping.
Frequently asked questions
What is chargeable weight?
Chargeable weight is the figure your shipment is actually billed on. It is the greater of the actual (gross) weight and the volumetric (dimensional) weight, so light but bulky cargo pays for the space it takes.
What is the chargeable weight formula for air freight?
First find the volumetric weight: length × width × height in centimeters, divided by 6000, gives kilograms. Then compare it with the actual weight on the scale and bill the larger of the two.
Why is the air freight divisor 6000?
The 6000 divisor is the IATA standard dimensional factor: 1 cubic meter (1,000,000 cm³) ÷ 6000 = about 167 kg. It sets a fair density assumption so airlines aren't shipping near-empty space for the price of the goods' weight alone.
Is chargeable weight rounded up?
For air freight, yes — the chargeable weight is commonly rounded up to the next 0.5 kg. So 27.3 kg becomes 27.5 kg. Not every mode rounds, so confirm with your carrier.
How is chargeable weight different for sea freight?
LCL sea freight uses a revenue-ton rule instead of a divisor: you are billed on whichever is greater, the weight in metric tons or the volume in CBM (where 1 CBM = 1,000 kg). Road and courier shipments use their own divisors, often 5000 or 4000.
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