Convert Ton Register (ton reg) to Cubic Kilometer (km³) instantly.
About these units
Ton Register (ton reg)
A register ton, or ton register, is a unit of volume, not mass, equal to 100 cubic feet. It is used in maritime contexts to measure the internal capacity of ships—specifically cargo-carrying volume, not weight. Ship registries rely on register tons to calculate taxes, port fees, and cargo classifications. The unit dates back to 19th-century maritime law, where consistent volumetric measurement was critical for international shipping regulation. Despite changes in global trade and containerization, register tons remain important for historical vessel documentation, as well as for understanding older merchant and naval ship specifications.
Cubic Kilometer (km³)
A cubic kilometer represents one billion cubic meters, making it a colossal volume unit used in geology, hydrology, glaciology, and planetary science. Large lakes, ice sheets, magma chambers, and atmospheric water content are often measured in km³. Earth's total ocean volume—about 1.335 billion km³—illustrates the unit's utility in describing planetary-scale systems. The km³ gives scientists a manageable number when dealing with natural features too massive for cubic meters or liters to express conveniently.