Tonnage

1. Any of various measures of the size or cargo-carrying capacity of a ship in terms of weight or volume.
2. Builder's Old Measurement, also tons burden: a volumetric measurement of cubic capacity used to calculate the cargo capacity of a ship, used in England and later the United Kingdom, from approximately 1650 to 1849 and in the United States from 1789 to 1864. It estimated the tonnage of a vessel based on her length and maximum beam. The British formula yielded a slightly higher value than the U.S. formula.
3. Deadweight tonnage: the total weight a vessel can carry, exclusive of the mass of the vessel itself.
4. Displacement tonnage: the total weight of a vessel.
5. Gross register tonnage: the total internal volume of a vessel, with one gross register ton equal to 100 cubic feet (2.8316846592 cubic meters).
6. Gross tonnage: a function of the volume of all of a ship's internal spaces.
7. Lightship or lightweight tonnage: the weight of a ship without any fuel, cargo, supplies, water, passengers, etc. on board.
8. Net register tonnage: the volume of cargo a vessel can carry.
9. Net tonnage: the volume of all cargo spaces on a ship.
10. Thames Measurement tonnage: the volume of a small vessel, calculated based on her length and beam.