Deadweight Tonnage

Deadweight Tonnage (DWT) is a unit of measurement for a ship's carrying capacity, referring to the total weight of cargo, fuel, fresh water, ballast water, spare parts, crew, and luggage that a ship can carry when at its full-load draft, i.e., the difference between a ship's total displacement and its light displacement. It reflects a ship's cargo-carrying capacity and operational efficiency, and is commonly used in chartering, ship sale and purchase, port charge calculation, and route stowage. Usage scenarios include: stipulating DWT in charter contracts to determine freight; using it as a valuation indicator in ship sale and purchase; and ports charging berthing fees based on DWT. Note: DWT is not equal to the actual cargo weight that can be loaded; fuel, fresh water, etc. must be deducted, hence the concept of 'Net Deadweight'. It is different from 'Gross Tonnage' (GT) and 'Net Tonnage' (NT), which are volumetric units used for tonnage taxes and registration. Difference: GT measures a ship's total internal volume, NT measures the volume of profitable space, while DWT measures weight-carrying capacity. Foreign trade practitioners need to accurately understand this term based on cargo weight, route restrictions, and contract terms to avoid cost miscalculations caused by conceptual confusion.