TBW

TBW is an acronym that can refer to multiple concepts, depending on the context. The two most common meanings are Total Body Water in physiology and Terabytes Written in data-storage technology.

Total Body Water (TBW) is the amount of water contained in the body's tissues, including intracellular water (inside cells) and extracellular water (outside cells). TBW is typically expressed as a percentage of body weight and varies with age, sex, and body composition. In healthy adults, TBW ranges roughly from 45 to 60 percent of body weight; it is higher in infants and tends to decrease with age. TBW can be measured by dilution methods using isotopically labeled water, such as deuterium oxide, and it informs assessments of hydration, nutrition, and fluid balance in clinical settings.

Terabytes Written (TBW) is a durability rating for flash-based storage devices such as solid-state drives. It represents the total amount of data that can be written to the device over its expected lifetime. Endurance depends on NAND type, process node, wear leveling, temperature, and workload characteristics. TBW is often provided with warranty terms, but it does not capture all reliability factors. Consumer SSDs typically report hundreds of terabytes of written data, while enterprise drives may specify hundreds of petabytes.