OCEAN VESSELS & CAPACITY
Deadweight Tonnage (DWT)
Deadweight tonnage measures a vessel’s carrying capacity by weight at a specified loading condition. It includes variable loads such as cargo, fuel, water, ballast and stores, rather than only saleable cargo.
DEADWEIGHT TONNAGE IN PRACTICE
- Read the vessel measureConfirm the stated condition and weight unit.
- Account for other loadsAllow for fuel, water, ballast and stores.
- Check voyage limitsReview draught, stability, space and loading restrictions.
Use the agreed units, actual records and approved procedures for your operation.
A WORKED EXAMPLE
Carrying capacity is not cargo alone.
For a simplified vessel example, a stated 10,000-unit deadweight allowance includes 2,000 units of non-cargo loads. The arithmetic leaves 8,000 for cargo by weight, before other constraints. This is an illustration, not a loading approval or a prediction of an actual ship’s cargo capacity.
WHAT THIS MEANS FOR YOUR QUOTE
Agree the requirement before comparing quotes
Use the actual shipment, stock and service requirements. Record the billing unit, included work and responsibility for exceptions.
A LITTLE MORE CONTEXT
Questions about Deadweight Tonnage
Is DWT only cargo weight?
No. It includes other variable loads.
Is DWT the same as gross tonnage?
No. They measure different things.
Does DWT establish container-slot capacity?
No. Slot and space limits require separate information.
Source & example notes
IMO: Fourth Greenhouse Gas Study, vessel load methodology.
Sources provide background on the linked topic. Product documentation describes a particular implementation; confirm the rules, contract and procedures that apply to your operation.
Quantities, costs and scenarios are illustrative, not operating targets, approved handling instructions or guarantees. Source guidance reviewed 22 October 2026.
Last updated: · 3PL Hub
