Enter your cargo
Add a row for each different carton or pallet size. Gross weight per piece is required — chargeable weight cannot be determined without it.
How chargeable weight works
Every carrier sells two things at once: mass and space. An aircraft reaches its volume limit long before its weight limit when it is loaded with pillows, and reaches its weight limit long before its volume limit when it is loaded with machine parts. Chargeable weight is how the carrier gets paid for whichever constraint you consume.
Air freight
Volumetric weight (kg) = (L × W × H in cm) ÷ divisor. The IATA divisor for general cargo is 6000, which means 6,000 cm³ — six litres — is treated as one kilogram. Compare that with the actual gross weight and the carrier bills the higher of the two, rounded up to the next 0.5 kg.
Sea LCL
Revenue tons (W/M) = the greater of CBM and metric tons. Sea freight uses a 1:1 relationship instead of a divisor: one cubic metre is treated as one metric ton. Anything lighter than 1,000 kg per cubic metre bills on volume.
Worked example
Eight cartons, each 80 × 60 × 40 cm, gross weight 18 kg each.
- Volume per carton: 80 × 60 × 40 = 192,000 cm³
- Volumetric weight per carton at 6000: 192,000 ÷ 6,000 = 32 kg
- Total volumetric weight: 32 × 8 = 256 kg
- Total gross weight: 18 × 8 = 144 kg
- Air chargeable weight: the greater figure, so 256 kg — billed on volume
- As sea LCL: 1.536 CBM against 0.144 tons, so 1.536 revenue tons — also billed on volume
At a density of roughly 94 kg per cubic metre, this cargo is well below the 167 kg/m³ air break-even point, so volume wins comfortably in both modes.
Break-even densities
Whether volume or weight wins is purely a question of cargo density. These are the thresholds:
| Mode / divisor | Break-even density | Below this, you are billed on | Above this, you are billed on |
|---|---|---|---|
| Air — divisor 6000 | 167 kg per m³ | Volume | Gross weight |
| Air — divisor 5000 | 200 kg per m³ | Volume | Gross weight |
| Air — divisor 4000 | 250 kg per m³ | Volume | Gross weight |
| Sea LCL — W/M | 1,000 kg per m³ | Volume (measurement) | Weight |
Most manufactured goods in retail packaging fall between 100 and 250 kg per cubic metre, which is why air shipments so often bill on volume while the same cargo bills on volume by sea as well. Only genuinely dense freight — tiles, castings, liquids in drums, machinery — crosses the sea threshold.
What the calculator does not include
The figure produced here is the chargeable weight, not the invoice. Carriers apply several additional rules on top:
- Minimum charges. Nearly every air lane has a minimum charge, so a 4 kg shipment may be billed as though it were 45 kg.
- Weight breaks. Rates step down at thresholds such as 45, 100, 300, 500 and 1,000 kg. It is common for a 95 kg shipment to cost more than a 100 kg one, so it can be worth declaring up to the next break.
- Overlength and overweight surcharges. Pieces beyond an aircraft door's dimensions or a single-piece weight limit attract handling premiums or require a freighter.
- Sea LCL minimums. Consolidators normally apply a one revenue ton minimum, sometimes two on long-haul lanes.
Feed the chargeable figure into our freight cost estimator along with the rate you have been quoted to model the full cost.