Water Intake Calculator
Calculate your recommended daily water intake
Your Daily Water Intake
How to Use
- Enter your body weight in kilograms.
- Select your typical daily activity level.
- Choose the climate you live in or work in.
- Click 'Calculate Water Intake' to get your recommendation.
- View your result in both milliliters and number of cups.
About Hydration
Why Water Matters
Water makes up about 60% of the human body and is essential for nearly every bodily function. It regulates body temperature, transports nutrients, flushes waste products, lubricates joints, and supports digestion. Even mild dehydration (1–2% of body weight) can impair cognitive performance and physical endurance.
Daily Water Needs
The base recommendation is approximately 35 ml per kg of body weight per day. This increases with physical activity, hot weather, illness, pregnancy, and breastfeeding. The popular '8 glasses a day' rule is a simplified guideline, but individual needs vary significantly based on body size and activity.
Activity and Climate Effects
Physical activity increases water needs due to sweat loss. Light activity adds ~350 ml, moderate adds ~700 ml, and vigorous exercise can require an additional liter or more. Hot and humid climates also significantly increase sweat loss. During exercise in heat, drink 150–250 ml every 15–20 minutes.
Signs of Dehydration
Dark yellow urine is one of the most reliable signs of dehydration. Others include thirst, dry mouth, headache, dizziness, decreased urine output, and fatigue. Severe dehydration can cause rapid heartbeat, confusion, and fainting. Aim for pale yellow urine as an indicator of good hydration.
Key Features
- Personalized calculation based on weight and activity
- Adjusts for climate and environmental factors
- Shows result in both ml and cups for convenience
- Visual cup representation for easy daily tracking