Water Intake Calculator
How much water to drink daily based on weight, activity, and climate.
A general hydration estimate, not medical advice — needs vary by individual and health condition. Consult a doctor if you have a medical reason to track fluid intake closely.
Recommended daily intake
3 L
In glasses (~250 ml)
12 glasses
Where the total comes from
For informational and educational purposes only — not medical advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
How this is calculated
The baseline uses 35 ml per kilogram of body weight — the upper end of the commonly cited 30–35 ml/kg range. Exercise adds roughly 350 ml per 30 minutes, within the American College of Sports Medicine's guidance of 400–800 ml per hour of activity. Hot or humid climates add a flat 500 ml/day for extra fluid lost to sweat. This covers water from all sources, including food — you don't need to hit the number from drinking alone.
Frequently asked questions
Is there one correct daily water intake for everyone?
No single number fits everyone — needs scale with body weight, activity level, and climate, which is why this calculator asks for all three rather than giving a flat "8 glasses a day" answer, which is a popular but oversimplified rule of thumb.
Does this count water from food and other beverages?
This estimates total fluid needs; roughly 20% of daily water intake typically comes from food in a normal diet. If you eat a lot of water-rich foods (fruit, soup, vegetables), your actual drinking-water need may be somewhat lower than the raw total shown.