Water Intake Calculator
Enter your body weight, choose your typical activity level, and optionally flag hot weather, and this calculator gives you a general daily water intake target in liters — plus the equivalent number of glasses.
How it works
Your baseline need is estimated from your body weight (about 33 ml per kilogram), then scaled up for how active you are, from sedentary to very active. If you flagged hot weather, an extra 0.5 liters is added to cover additional fluid loss from sweating.
Tip
You don't need to hit this number from plain water alone — herbal tea, milk, soup and water-rich foods like fruit and vegetables all count toward your daily fluid intake.
Is this medical advice?
No. This is a general rule-of-thumb estimate, not medical advice — individual needs vary widely with health conditions, medications, pregnancy, breastfeeding and climate. Talk to a doctor if you have specific health concerns about your fluid intake.
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