What fraction of total body water does the extracellular fluid (ECF) compartment account for?

1. Body water splits into ICF (about 60 percent) and ECF. 2. Since ICF is roughly 60 percent, the remainder logically approximates one-third. 3. The ECF accounts for the other one-third of body water content. 4. So the answer is one-third. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 26 "Fluid, Electrolyte, and Acid-Base Balance", p.1250 §Extracellular Fluid_