Volumetric Weight

Volumetric weight, also known as dimensional weight or dim weight, is a notional weight calculated from a shipment's dimensions. It exists because aircraft holds and containers fill up on space before they reach their weight limit, so carriers price light, bulky cargo as if it weighed more. IATA's general rule for air cargo is to divide the volume in cubic centimeters by 6,000; the carrier then charges on whichever is higher, the volumetric weight or the actual weight.

How to calculate it

1. Measure each piece at its outermost points in centimeters, including the pallet and any overhang
2. Multiply length × width × height to get cubic centimeters, and multiply by the number of identical pieces
3. Divide by 6,000 to get volumetric weight in kilograms

Example: a pallet of 120 × 80 × 100 cm is 960,000 cm³, or 0.96 cubic meters. Divided by 6,000 that is 160 kg. If the pallet actually weighs 120 kg, it is billed at 160 kg. At the 6,000 divisor one cubic meter counts as about 167 kg, so anything less dense than that pays on volume.

In inches: 6,000 cm³ is about 366 cubic inches, so cubic inches ÷ 366 gives kilograms, and cubic inches ÷ 166 gives pounds.

Divisors other than 6,000

6,000 is the IATA standard, but it is not universal. Some carriers use 5,000, which counts a cubic meter as 200 kg and makes bulky cargo dearer, and express and courier services set their own formulas for small parcels, which can vary by origin and destination. The carrier's tariff decides, so check which divisor a quote assumes.

Volumetric weight in ocean LCL

Ocean LCL applies the same idea at a much gentler ratio. Consolidators charge per revenue ton under the weight-or-measure (W/M) rule, where one cubic meter (CBM) counts as 1,000 kg. The same 0.96 m³ pallet that bills as 160 kg by air bills as 0.96 revenue tons by sea unless it weighs more than 960 kg. Full containers are priced per box, so volumetric weight does not apply to FCL.

Volumetric weight vs chargeable weight

Volumetric weight is one of two inputs. Chargeable weight is the result: the greater of the volumetric weight and the actual gross weight. The air waybill shows the gross weight and the chargeable weight the rate is applied to.

How to keep it down

• Right-size cartons and cut empty space; ship furniture and fixtures knocked down
• Avoid oversized pallets and overhang, which count at their outer dimensions
• Give accurate dimensions at booking, because the airline or handler can re-measure at acceptance
• Compare modes: cargo that pays on volume by air may pay on weight, and far less, as LCL

The chargeable weight and CBM calculator works out volumetric weight at 1:6000 or 1:5000 from your carton list, alongside total CBM and LCL revenue tons. See air freight and LCL ocean freight for how each is quoted.