Deadweight Tonnage (DWT)
Deadweight Tonnage (DWT) is the total weight a ship can carry when loaded to its maximum permitted draft — including cargo, fuel (bunkers), fresh water, ballast, stores, crew and their effects. It is the difference between the ship's loaded and empty (lightship) displacement, expressed in tonnes.
DWT is the standard measure of a cargo ship's carrying capacity and the way vessels are commonly sized and compared (e.g. a "50,000 DWT bulk carrier"). It is central to chartering and freight economics — the charter hire and cargo intake both scale with deadweight. Note that DWT is total carrying weight, not just cargo: usable cargo deadweight is DWT minus the weight of bunkers, water and stores needed for the voyage.
Deadweight is how the market sizes and prices a cargo ship — hire rates, cargo intake and freight all scale with it. Knowing the difference between total DWT and usable cargo deadweight (after bunkers, water and stores) is what turns a headline capacity figure into a real cargo-planning number.
Is DWT the weight of the ship?
No — it is the weight the ship can carry (cargo plus fuel, water, stores and crew), not the weight of the vessel itself.
How is DWT different from gross tonnage?
DWT measures carrying capacity in weight; gross tonnage measures the ship's enclosed volume. They are unrelated units.