Volumetric Weight and Chargeable Weight Explained

Volumetric weight is the weight a carrier charges for the space a shipment takes up. For air freight it is length × width × height in centimetres divided by 6,000; for express couriers it is usually divided by 5,000. The chargeable weight is whichever is greater, the actual weight or the volumetric weight, and that figure, not the weight on your scale, sets the price.

If you only want the number for your cartons, our free CBM and chargeable weight calculator works it out for air, express and sea at once. The rest of this guide explains the rules behind it, with worked examples you can check by hand.

What is volumetric weight?

An aircraft hold fills up by volume long before it reaches its weight limit if the cargo is light, so airlines price space as if it had a weight. The standard air cargo rule uses a factor of 6,000 cubic centimetres per kilogram, which is the same as charging at least about 167 kg for every cubic metre. Express couriers use 5,000, or 200 kg per cubic metre, which is why the same box costs more by express on a per-kilo basis.

Measure the outside of each packed carton at its widest points, in centimetres. If your supplier gives inches, multiply by 2.54 first; for pounds, multiply by 0.4536 to get kilograms. On a pallet, measure the whole loaded pallet, including the base and any overhang.

How is chargeable weight decided?

Work out two numbers for the shipment: the total actual gross weight and the total volumetric weight. The larger one is the chargeable weight. Dense goods such as metal parts or tiles are charged by actual weight; light, bulky goods such as pillows, lampshades or plastic storage boxes are charged by volume.

Airlines usually round the chargeable weight up to the next 0.5 kg, and express rates step in 0.5 kg bands. A single carton of 45 × 35 × 30 cm holds 47,250 cubic centimetres. By air that is 47,250 ÷ 6,000 = 7.875 kg, which rounds up to 8 kg; by express it is 47,250 ÷ 5,000 = 9.45 kg, which rounds up to 9.5 kg.

Worked examples

In the first example the carton is 60 × 50 × 40 = 120,000 cubic centimetres. Divided by 6,000 that is 20 kg, more than the 18 kg it weighs, so air freight charges 20 kg. In the second, ten cartons of 60,000 cubic centimetres make 600,000 in total: 100 kg by air, less than the actual 120 kg, so the actual weight is charged. In the third, five cartons of 210,000 cubic centimetres make 1,050,000: the goods weigh 45 kg but are charged as 175 kg by air and 210 kg by express, about 3.9 and 4.7 times the actual weight.

Why do express and air freight give different answers?

The divisor is the whole difference. Because 5,000 is smaller than 6,000, express turns the same volume into a volumetric weight one fifth higher, as the 175 kg and 210 kg in the third example show. For small, dense parcels this rarely matters and express is still the quickest option. For bulky cartons of 20 kg or more, air freight usually costs less per chargeable kilogram, and its per-kg rates fall at higher weight breaks. Our published air rates start from a minimum chargeable weight of 22 kg to the USA, Canada and Australia, and 11 kg to New Zealand.

How is sea freight charged?

LCL sea freight uses weight or measure, often written W/M: each cubic metre is compared with 1,000 kg, and the larger figure is charged, plus origin and destination charges. A shipment of 2.4 CBM weighing 1,800 kg is charged as 2.4 units, because 2.4 CBM is greater than 1.8 tonnes. A shipment of 1.5 CBM weighing 2,100 kg is charged as 2.1 units, by weight. Full containers are priced per container instead; our LCL vs FCL guide explains when a container becomes the cheaper choice.

How can you lower your chargeable weight?

• Ask suppliers to use cartons that fit the product, without empty space or oversized outer boxes.
• Combine small cartons from several orders into fewer, fuller cartons before they ship.
• Check whether a pallet is needed by air: the base and the air above uneven stacks count as volume.
• For light, bulky goods, compare air with sea or rail, where volume costs far less.
• Get dimensions from the packed goods, not the product sheet, so the quote matches the final bill.

At our Shenzhen warehouse we receive goods from several suppliers, check them, and can repack and relabel cartons before dispatch, which is often where volumetric weight comes down. See warehousing and consolidation for how it works; storage terms and handling charges are confirmed with your quote.

Check your own cartons

Enter your carton sizes, quantities and weights in the calculator to see the total CBM, the volumetric weight by air and by express, and the chargeable weight for each. Then send the same details with a quote request, and a specialist confirms the price for your route.