Tare weight

Tare is the empty weight of whatever holds your cargo — a shipping container, a trailer, a pallet, even a carton. Gross weight = net (cargo) + tare. Every ISO container has its tare stenciled on the door (a 20ft box is roughly 2,200 kg, a 40ft high cube about 3,900 kg), and that exact figure feeds two calculations that carry legal weight: SOLAS VGM declarations and road weight limits.

Use the door figure, not a generic average — containers of the same size vary by hundreds of kilograms between manufacturers and build years. For trucking, tare determines payload: an 80,000 lb US gross limit minus a 33,000–35,000 lb tractor-trailer tare leaves roughly 45,000 lb for freight.