Water Intake Calculator
Calculate your recommended daily water intake based on body weight, activity level, and climate. Get results in mL, liters, ounces, and cups.
Why Hydration Matters
- Cognitive function — even mild dehydration (1–2%) impairs concentration and memory
- Physical performance — dehydration reduces endurance and strength
- Digestion — water aids nutrient absorption and prevents constipation
- Temperature regulation — sweating and respiration require adequate fluid intake
Daily Water Intake Guidelines
| Organization | Men | Women |
|---|---|---|
| US National Academies | 3.7 L (125 oz) | 2.7 L (91 oz) |
| WHO | ~2.5 L | ~2.2 L |
| European Food Safety Authority | 2.5 L | 2.0 L |
These are total water from all sources including food, which contributes roughly 20% of daily intake.