Net TonnageNT
A volume-based measure of the space available for cargo and passengers, derived from gross tonnage.
Net tonnage (NT) estimates the useful earning volume of a ship — the cargo and passenger spaces — by deducting non-revenue volumes (engine room, crew accommodation, navigation spaces) from gross tonnage under the tonnage convention formula.
Like GT it is dimensionless, not a weight. NT is widely used to assess port dues and canal tolls because it is meant to reflect the commercial capacity of the vessel.
Also known as: net tons, NT, net registered tonnage.
Related terms
Plain-English reference definition — our own explanation of a standard shipping concept, not a licensed source or legal advice. See the full glossary or the broader maritime dictionary.
Last reviewed: June 2026.