Free Water Clearance (CH₂O) Calculator
Renal free water clearance for assessing water handling
When to use it
Use to evaluate renal water excretion capacity in dysnatremia workup.
Category
Electrolytes & Acid-Base
References
- Rose BD, Post TW. Clinical Physiology of Acid-Base and Electrolyte Disorders. 5th ed. McGraw-Hill; 2001. https://www.mheducation.com/highered/mhp/product/clinical-physiology-acid-base-electrolyte-disorders.html
- Halperin ML, Goldstein MB. Fluid, Electrolyte and Acid-Base Physiology. 4th ed. https://shop.elsevier.com/books/fluid-electrolyte-and-acid-base-physiology/halperin/978-1-4160-2442-2
About NephroMind
This calculator is part of NephroMind, a free clinical decision-aid platform from the Arab Society of Nephrology and Renal Transplantation (ASNRT) — over 128 bedside nephrology calculators plus a renal drug-dosing database, coded by a practicing transplant nephrologist.