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Dehydration Calculator
Estimate your fluid deficit and how much water and electrolytes you need to get back to balance.
Educational guidance only — not medical advice. This calculator estimates an average fluid deficit and must never be used to force large amounts of water. Drinking far more fluid than your kidneys can excrete can dilute your blood sodium to dangerous levels (hyponatraemia), which is life-threatening. If you have signs of severe dehydration — confusion, fainting, no urine, vomiting or heat stroke — seek professional medical help immediately instead of relying on this tool.