What is chargeable weight?
Transport capacity is limited by both weight and space. A pallet of pillows weighs little but fills a lot of an aircraft hold, so carriers convert volume into a notional volumetric weight (also called dimensional or DIM weight). The chargeable weight is the higher of the actual gross weight and the volumetric weight, and that is what your rate is multiplied by.
Formulas by mode
Air freight: L × W × H (cm) ÷ 6,000 = volumetric kg Express courier: L × W × H (cm) ÷ 5,000 = volumetric kg Road groupage: L × W × H (cm) ÷ 3,000 = volumetric kg (common in Europe) Sea LCL: revenue tons = max(CBM, gross weight in tonnes)The IATA air divisor of 6,000 cm³/kg is the same as 166.67 kg per cubic metre. In inches and pounds the US equivalents are about 166 in³/lb for air and 139 in³/lb for express. Express integrators and some airlines set their own divisors, so always check the carrier’s tariff. Road ratios vary by country and operator (3,000 and 4,000 are both common).
For sea LCL, 1 CBM is treated as 1,000 kg, and the shipment is charged per weight or measurement (W/M) — whichever gives more revenue tons.
Worked example
One carton, 100 × 80 × 60 cm, actual weight 50 kg:
- Volume: 1.0 × 0.8 × 0.6 = 0.48 m³
- Air volumetric: 480,000 ÷ 6,000 = 80 kg → chargeable 80 kg (volumetric)
- Express volumetric: 480,000 ÷ 5,000 = 96 kg → chargeable 96 kg
- Sea LCL: 0.48 CBM vs 0.05 t → 0.48 revenue tons, though most forwarders apply a 1 CBM minimum
How to reduce chargeable weight
- Right-size cartons and remove void fill; every centimetre on each side compounds.
- For mixed shipments, carriers usually compare total actual weight with total volumetric weight across all pieces, so consolidating dense and light items can help.
- Check pallet heights. Air pallets that do not stack waste space and may be charged to full height.
Frequently asked questions
What is the volumetric divisor for air freight?
Most airlines and forwarders use the IATA standard of 6,000 cm³ per kg (1:6000), equal to 166.67 kg per cubic metre. Express couriers commonly use 5,000.
How do I calculate volumetric weight in inches and pounds?
Multiply length, width and height in inches, then divide by 166 for air freight or 139 for most express services. This calculator does the conversion for you when you switch to inches / lb.
Is chargeable weight calculated per piece or per shipment?
For air freight it is usually calculated on the whole shipment: total actual weight versus total volumetric weight. Some express services compare per package. This calculator uses shipment totals.
What does W/M mean in sea freight?
Weight or Measurement. LCL ocean freight is charged per revenue ton, which is the greater of the volume in cubic metres and the weight in metric tonnes.
Do carriers round chargeable weight?
Yes. Air freight is commonly rounded up to the next 0.5 kg, and express services often round up to the next 0.5 or 1 kg. Dimensions may also be rounded up to the nearest centimetre or inch.