Air Volumetric Weight: Which Weight Sets Your Freight Rate?

Air freight is charged on chargeable weight, which is the higher of the shipment’s actual gross weight and its volumetric (dimensional) weight. For general air cargo, volumetric weight is (length × width × height in cm) ÷ 6000. That is why light but bulky cargo often costs more than its scale weight suggests.

Key takeaways

• Chargeable weight is the greater of actual gross weight and volumetric weight.
• The general air cargo formula referenced by IATA is (L × W × H cm) ÷ 6000, so 1 CBM counts as roughly 167 kg.
• Express couriers such as DHL Express use ÷5000 (1 CBM = 200 kg), which gives a higher volumetric weight for the same carton.

What is volumetric weight?

Volumetric weight turns the space a shipment takes up into a notional weight. Aircraft have limited cargo space, so pricing on scale weight alone would let light, bulky goods fill the hold cheaply. Carriers and forwarders therefore compare actual and volumetric weight and charge on whichever is higher.

Sea LCL works on the same “greater of the two” idea, but with a different conversion factor. The ocean rules are covered in CBM Meaning in Shipping: How Is Freight Volume Counted?.

How do you calculate air volumetric weight?

For general air cargo, multiply the length, width and height in centimetres and divide by 6000. Compare the result with the actual gross weight, and the higher figure becomes the chargeable weight. Both IATA and DHL Global Forwarding give ÷6000 as the air cargo standard.

Volumetric weight (kg) = (length cm × width cm × height cm) ÷ 6000

This treats one cubic metre as about 166.67 kg, usually rounded to 167 kg. For several cartons, add up the total volume and divide once. Measure the outermost dimensions including packaging, and include the pallet if the goods are palletised.

Under IATA’s air cargo tariff rules (TACT), chargeable weight is rounded up. A fraction of 0.5 kg or less is rounded up to the next half kilogram, a fraction above 0.5 kg goes to the next full kilogram, and exactly 0.5 kg stays as it is.

How much difference does it make in practice?

A 100 cm × 80 cm × 60 cm carton weighing 50 kg is charged as 80 kg. Its volumetric weight is higher than its actual weight. Here is the calculation step by step.

1. Volume: 100 × 80 × 60 = 480,000 cm³
2. Volumetric weight: 480,000 ÷ 6000 = 80 kg
3. Chargeable weight: the higher of 50 kg and 80 kg = 80 kg

If the carton had weighed 100 kg, the chargeable weight would be 100 kg. With the rounding rule, a volumetric weight of 79.3 kg is charged as 79.5 kg and 79.6 kg as 80 kg. The final price also depends on weight-break rates and minimum charges, so weight alone does not tell you the bill.

Category	Formula	1 CBM equals	Typical use
General air cargo	(L×W×H cm) ÷ 6000	about 167 kg	Forwarder and airline freight
Express courier	(L×W×H cm) ÷ 5000	200 kg	DHL Express and similar urgent parcels
Sea LCL	Higher of CBM or tonnes	1,000 kg	Less-than-container-load sea freight

How is express courier pricing different from air cargo?

General air cargo uses ÷6000, while express couriers usually use ÷5000. A smaller divisor means a bigger volumetric weight, so the same carton comes out 20% heavier on a courier rate. The 100 × 80 × 60 cm example is 80 kg at ÷6000 but 96 kg at ÷5000.

DHL Express states in its service conditions that it divides piece volume by 5000 and charges each piece on the higher of actual or volumetric weight. Other couriers and contract rates may differ, so check the divisor printed on your quote first.

What are the most common volumetric weight mistakes?

The usual mistakes are measuring inside rather than outside dimensions and missing a different divisor between the quote and the invoice. Bulging cartons, handles and protruding packaging all count toward the dimensions. If you use a pallet, its volume and weight are included too.

• General air cargo usually adds up the total volume, but couriers may rate each piece separately.
• A minimum charge can apply to small shipments. Under IATA TACT rules, if the calculated charge is lower than the minimum charge, the minimum charge applies.
• Mixing inches and centimetres or leaving out a carton throws the quote off badly.
• Giving your forwarder accurate dimensions and weights before booking helps avoid billing surprises.

Can better packaging lower your air freight cost?

Yes. Volumetric weight depends on carton size, so cutting empty space and shrinking the outer dimensions lowers the chargeable weight. Just keep enough protection for the goods.

Use right-sized cartons for light items, or consolidate several products into fewer, denser packages. When comparing quotes, line them up on the same divisor, and if you ship the same cargo regularly, ask your forwarder about weight-break rates. For samples, pack them the way you would pack the full order so the estimate holds. For a wider view of mode choice, see Shipping from Korea: Sea vs Air, and for terminal costs, THC meaning and who pays.

FAQ

Is air volumetric weight always calculated with ÷6000?

General air cargo usually uses ÷6000. Express couriers commonly use ÷5000, and some contracts or carriers use other factors. Check the quote and the air waybill (AWB).

Do I pay on actual weight or volumetric weight?

You pay on whichever is higher. Light, bulky cargo is charged on volumetric weight, and dense, heavy cargo on actual weight.

How do I calculate several cartons?

For general air cargo, add up the volume of every carton and divide the total by 6000. Couriers may calculate each piece separately, so check the carrier’s rule.

How many kilograms is 1 CBM in air freight?

About 167 kg under ÷6000 and 200 kg under ÷5000. Cargo lighter than that density is charged on volumetric weight.

Sources

• IATA, Air Cargo Tariffs and Rules: What You Need to Know
• DHL Global Forwarding, Calculating chargeable weights for air, sea, road and rail (Korean page)
• DHL Express, Standard Service Conditions (volumetric divisor 5000, per piece)
• DHL Express, How do I calculate the volumetric weight? (1 m³ = 200 kg)
• ASEAN, Calculation of Air Freight (training material on IATA TACT weight rounding and minimum charges)