extracellular ~20%: (plasma ~5%, interstitial fluid ~15%) intracellular ~40% % of body mass
||OS. Andersen, "Cellular Electrolyte Metabolism", in Encyclopedia of metalloproteins, eds. Robert H Kretsinger Vladimir N Uversky E A Permi?a?kov, Springer 2013 pp.580-587 p.582 left column top paragraph
||"In mammals and other multicellular animals, about 60% of the body mass is water, which is distributed between two major fluid compartments (Fig. 2): the extracellular compartment (~20% of the body mass), the environment in which the body cells live, which is divided into the intravascular fluid compartment or plasma (~5% of the body mass) and interstitial fluid (~15% of the body mass) and the intracellular compartment (~40% of the body mass)."