What a container's tare adds to freight depends on what the carrier bills on. In air cargo the invoice uses the higher of actual weight and volumetric weight (length × width × height ÷ 6000, the IATA standard), and in an insulated container the wall thickness takes up volume without carrying any product.
Take a container with outer dimensions of 60 × 40 × 40 cm: its volumetric weight is 96,000 cm³ ÷ 6000 = 16 kg.
- Loaded weight 12 kg: the invoice is for 16 kg, and the amount stays the same even if the container is 2 kg lighter.
- Loaded weight 20 kg: the invoice is for 20 kg, and tare is paid for kilogram by kilogram.
In consolidated sea freight the charge follows the volume used (m³), and for part-load road freight the divisor depends on the carrier. A full truck is priced per trip, so tare starts to matter only once the vehicle's payload limit is reached.
Compare containers on freight per unit of product (net product kilos ÷ freight); a heavier container that holds cold longer and needs fewer plates can come out lighter overall.
