Convert Ton Register (ton reg) to Petaliter (PL) 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.
Petaliter (PL)
A petaliter represents 10¹⁵ liters, a massive unit used to quantify the total water content of oceans, polar ice sheets, or planetary atmospheres. Oceanographers may describe the Pacific Ocean's volume or the total ice volume of Antarctica in petaliters; these scales cannot be expressed meaningfully in smaller units without imposing huge, impractical numbers. The PL is also sometimes used in astronomy to approximate ocean-like features on other worlds, such as subsurface oceans on Europa or Enceladus. It represents one of the largest practical volumetric units before entering pure theoretical measurement.