How much water should you drink daily?
Calculate your personalized daily fluid intake based on clinical benchmarks from the NASEM (US), EFSA (Europe), and DGE (Germany)—with transparent formulas and peer-reviewed citations.
≈ 88 fluid oz (from water, herbal tea & beverages)
100% on-device private health archive. Zero cloud upload.
If you have congestive heart failure, chronic kidney disease (CKD), or are on diuretic medications, your physician may prescribe a strict fluid restriction (typically 1.5–2.0 L/day). Always follow your nephrologist or cardiologist's tailored fluid prescription.
How we calculated this: Clinical Citations & Formulas
Unlike generic fitness calculators that promote arbitrary rules, Subra Space AI anchors its hydration model on published dietary reference guidelines from the United States, the European Union, and Germany:
NASEM / Food & Nutrition Board (IOM)
Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (National Academies Press). Established baseline total fluid intakes of 2.7L for women and 3.7L for men.
EFSA Panel on Dietetic Products (NDA)
Scientific Opinion on Dietary Reference Values for Water. Established that ~80% of total daily fluid intake comes from drinking water and beverages, with 20% derived from solid food moisture.
DGE (Deutsche Gesellschaft für Ernährung)
DGE-Referenzwerte für die Zufuhr von Wasser. Recommends direct beverage consumption of approximately 35 ml per kg body weight under moderate climate conditions for healthy adults.