Water Deficit Calculator
This tool estimates a patient’s water deficit in cases of hypernatremia.
Estimated Water Deficit:
Liters
*The ideal plasma sodium concentration is assumed to be 140 mEq/L.
The Water Deficit in Hypernatremia Calculator is a valuable tool for clinicians to estimate a patient’s free water deficit. This is a critical first step in managing hypernatremia, a condition characterized by a high plasma sodium concentration, which can lead to serious neurological complications. The calculator uses a simple but effective formula that takes into account the patient’s gender, weight, and current plasma sodium level to approximate the amount of water needed to restore fluid balance and return the sodium concentration to a safe level, thus helping to guide appropriate fluid resuscitation.
References:
- Adrogué, H. J., & Madias, N. E. (2000). Hypernatremia. The New England Journal of Medicine, 342(20), 1493–1499.
- Sterns, R. H. (2015). Hypernatremia: Pathophysiology and treatment. International Journal of Nephrology, 2015, 232067.


