Air freight is charged on chargeable weight — the greater of a shipment’s actual gross weight and its volumetric weight. Light but bulky cargo is billed on the space it occupies, so getting this number right is essential for accurate quoting and AWB verification.
How it works
For each piece, volumetric weight uses the IATA divisor of 6000 when dimensions are in centimetres:
volumetric kg = (length × width × height in cm) / 6000
chargeable = max(gross weight, volumetric weight)
piece total = chargeable × quantity
shipment total= sum of all piece totals
charge = shipment chargeable weight × rate per kg
The divisor 6000 reflects a billing density of 167 kg/m³. Below that density a shipment is “volume cargo” and is charged on its dimensions.
Example
A pallet 120 × 100 × 110 cm weighing 90 kg gross has a volumetric weight of 120 × 100 × 110 ÷ 6000 = 220 kg. Because 220 kg exceeds the 90 kg gross weight, the chargeable weight is 220 kg. At a rate of 3.50 per kg the line-haul charge is 770.
Why the 6000 divisor matters
The number 6000 is not arbitrary — it defines the crossover density. A box that is exactly as heavy as its volumetric equivalent weighs 1 kg per 6,000 cm³, which equals 166.7 kg per cubic metre. Cargo denser than this is billed on actual weight; cargo lighter than this (foam, pillows, empty packaging) is billed on volume. Knowing where your cargo sits relative to that density threshold helps you anticipate costs before measurement.
For context, consumer electronics boxes often fall just below the density threshold, making them volume cargo. Dense industrial components such as machinery parts or metal fittings are almost always actual-weight shipments. Mixed pallets benefit from this tool’s per-piece calculation, because each piece’s threshold is evaluated independently before summing.
5000 vs. 6000 divisor
Express integrators — DHL Express, FedEx, UPS — typically apply a 5000 divisor for international door-to-door parcels rather than the IATA 6000. A 5000 divisor raises the volumetric weight for any given box by 20%, meaning more shipments are billed by volume. If you are quoting or verifying an express waybill rather than an airport-to-airport AWB, switch the tool’s divisor to 5000. True air cargo under IATA convention uses 6000.
Multiple-piece shipments
Airlines charge on the total chargeable weight of the consignment, not piece-by-piece. This tool sums each line’s chargeable weight (piece chargeable × quantity) to give the shipment total. In practice, carriers round the final total up to the next 0.5 kg before applying the rate, which the tool also shows. Entering each piece type on a separate line lets you see which items are driving the chargeable weight — useful when consolidating or redesigning packaging.
Notes
Carriers usually round the final chargeable weight up to the next 0.5 kg. Express integrators sometimes use a 5000 divisor, which raises chargeable weight for the same box — switch the divisor if your carrier uses it. Surcharges and AWB fees are billed on top of the line-haul charge shown here.