How much water should I drink a day?

Most adults need 2 to 3.7 liters (8 to 15 cups) daily. The exact amount depends on weight, activity level, climate, and health conditions. A personalized calculator using body weight (33ml per kg) is more accurate than the generic '8 glasses' rule.

Is the 8 glasses of water a day rule accurate?

The 8-glasses rule (about 2 liters) is a rough starting point, not a scientific recommendation. A 50kg sedentary person and a 90kg athlete have very different hydration needs. Body-weight-based calculation is far more accurate.

Does coffee count toward daily water intake?

Yes. While caffeine is a mild diuretic, studies show coffee and tea still provide a net positive hydration effect. They count toward your daily total, though plain water remains the best choice.

How do I know if I'm dehydrated?

Check urine color: pale yellow means well hydrated, dark yellow means you need more water. Other signs include dry mouth, fatigue, headaches, and dizziness.

How much extra water do I need during exercise?

The American College of Sports Medicine recommends 350-500ml (12-17oz) of extra water for every 30 minutes of exercise. For workouts longer than 60 minutes, add electrolytes.

💧 Water Intake

Daily Water Intake Calculator

How much water should you drink a day? Get a personalized recommendation based on your body and lifestyle.

The average adult needs about 2.7 to 3.7 liters of water per day, according to the National Academy of Medicine (2024). However, individual needs vary widely based on body weight (approximately 33ml per kg), physical activity, climate, and health conditions such as pregnancy. About 20% of daily water intake typically comes from food.

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Weight (kg)

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