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Water Intake Calculator
💧 Water Intake Calculator
The 'drink 8 glasses a day' rule ignores body size, activity, and climate entirely. This estimates a daily water target based on your actual weight, how active you are, and where you live.
The base figure here (33ml per kg of body weight) comes from common clinical hydration guidance, then adjusts up for exercise-related sweat loss and hot/humid climates, or down slightly for colder conditions where thirst cues are naturally lower.
Frequently Asked Questions
Does this include water from food and other drinks?
No — this estimates water/fluid intake specifically. Food typically contributes another 20% or so of total hydration on top of this figure in a normal diet.
Is more water always better?
No — significantly overdrinking water can dilute sodium levels (hyponatremia) in rare cases, especially among endurance athletes. This target is a sensible range, not a minimum to exceed aggressively.
Why does activity level matter so much?
Sweat loss during exercise can easily exceed 1 liter per hour in hot conditions, which is why active or hot-climate adjustments add meaningfully more to the daily target than sedentary indoor conditions.
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