Water Intake Calculator
Enter your weight and daily active minutes for a baseline daily water intake target.
Not a diagnosis. See the Health & Fitness section intro for more on that.
How it's calculated
Baseline: 35 ml per kg of body weight, a commonly cited general guideline. On top of that, 355 ml (roughly 12 fl oz) per 30 minutes of activity is added to account for sweat loss during exercise.
This doesn't account for climate, individual sweat rate, pregnancy or breastfeeding, or medical conditions affecting fluid needs — all of which can meaningfully change the right target for a specific person.
Frequently asked
Does this count water from food and other drinks?
No — this is a target for water specifically. Food and other beverages also contribute to total hydration, so this baseline is intentionally a reasonable floor rather than total fluid intake.
Should I drink more in hot weather?
Generally yes — heat and humidity increase sweat loss beyond what this baseline accounts for. This calculator doesn't adjust for climate, so add more on hot days or when sweating heavily.