Why carriers invented it
A kilo of feathers and a kilo of steel cost the same to lift but not the same to carry: the feathers fill an aircraft hold long before the weight limit is reached. So carriers charge on whichever is greater — the actual weight, or a figure derived from the space the shipment occupies.
That derived figure is volumetric weight, and on light bulky cargo it is almost always the one you pay on.
The formulas
Always use the packed dimensions — the outside of the carton or pallet, including the pallet itself — not the product's own measurements.
| Mode | Formula | Equivalence |
|---|---|---|
| Air freight (IATA) | L × W × H (cm) ÷ 6,000 | 1 CBM = 167 kg |
| Courier / express | L × W × H (cm) ÷ 5,000 | 1 CBM = 200 kg |
| Ocean LCL | volume in CBM vs tonnes (W/M) | 1 CBM = 1,000 kg |
| Road freight | L × W × H (cm) ÷ 3,000 typically | 1 CBM = 333 kg |
A worked example
A carton of 80 × 60 × 50 cm weighing 45 kg, going by air.
Volume: 80 × 60 × 50 = 240,000 cm³. Divide by 6,000 and you get a volumetric weight of 40 kg. The actual weight is 45 kg, which is greater, so you are billed on 45 kg.
Now take the same box weighing 25 kg. The volumetric weight is still 40 kg, which is now greater, so you pay for 40 kg and 15 of those kilos are air.
How to reduce it
- Remove empty space: a box with 30% void is 30% of your bill spent moving nothing
- Size the carton to the product, not to what you had in the warehouse
- Disassemble where it is safe to, and pack flat
- Account for the pallet itself — its height counts toward the volume
- For air, compare the cost of repacking against the saving; it often pays for itself on the first shipment
The mistake that changes quotes
Giving the forwarder the product's dimensions rather than the packed ones is the single most common reason a quote changes after booking. The carrier remeasures at origin, and their figure is the one that counts.
Measure the outside of what will actually be handed over, including pallet and wrapping, and the quote you get will be the quote you pay.
Frequently asked questions
How do I calculate volumetric weight for air freight?
Multiply length × width × height in centimetres and divide by 6,000. Compare the result with the actual weight: you are billed on whichever is greater.
Why is my shipment billed on more than it weighs?
Because its volumetric weight is higher than its actual weight, which happens with light bulky cargo. The space it occupies costs the carrier more than the weight does.
Do the dimensions include the pallet?
Yes. Always use packed dimensions — the outside of the carton or pallet including the pallet itself and the wrapping. Quoting from product dimensions is the most common reason a quote changes after booking.
Free quote
Need Volumetric Weight?
Fill in the form and one of our team will come back to you within 24 hours with the best rate for your operation.
¿Necesitas ayuda con Volumetric Weight?
Cotización gratuita sin compromiso · Respuesta en menos de 24 horas