If you're considering air freight for any portion of your move, understanding volumetric weight is essential. It determines what you pay — and it's often more than you'd expect.
Volumetric weight (also called dimensional weight) is a pricing method used in air freight that charges based on the space a shipment occupies rather than its actual physical weight. Aircraft have a fixed volume; a large box of pillows weighs very little but takes up the same cargo space as a box of lead. Airlines use volumetric weight to ensure they're compensated for space consumed, not just mass carried.
The standard international air freight formula:
(Length cm × Width cm × Height cm) ÷ 5,000 = Volumetric weight in kg
Formula (imperial):
(Length in × Width in × Height in) ÷ 139 = Volumetric weight in lbs
You are billed on whichever is greater: actual weight or volumetric weight.
| Item | Dimensions | Actual Weight | Volumetric Weight | You Pay For |
|---|---|---|---|---|
| Box of books | 40×40×40 cm | 25 kg | 12.8 kg | 25 kg (actual wins) |
| Box of pillows | 80×60×50 cm | 4 kg | 48 kg | 48 kg (volumetric wins) |
| Wardrobe box | 120×55×100 cm | 20 kg | 132 kg | 132 kg (volumetric wins) |
Air freight is ideal for dense, high-value items (electronics, jewelry, important documents) where actual weight is the dominant factor. For bulky, lightweight household goods like clothing, bedding, lampshades, and pillows, volumetric weight makes air freight extremely expensive per piece. This is one of the main reasons air freight for a full household is rarely practical — sea freight, priced per cubic meter, is dramatically more cost-effective for large volumes.
Sea freight for household goods is typically priced per cubic meter (CBM) or per revenue ton (1,000 kg), whichever is greater — a similar concept but at dramatically lower rates per unit. The interaction between weight and volume still matters for sea freight pricing, but the per-unit cost is roughly 10–30× lower than air freight, making it practical for full household shipments.
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