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Water Intake Calculator
Calculate how much water you should drink daily based on your weight, activity, and climate.
Frequently Asked Questions
How much water should I drink daily?+
EFSA recommends about 2.0 L/day for women and 2.5 L/day for men from beverages, with additional water from food. Needs rise with exercise, heat, and breastfeeding.
How is personal water need calculated?+
A common rule of thumb is 30–35 ml per kg of body weight. Add 0.5–1 L per hour of intense exercise or hot-weather exposure.
Do coffee and tea count toward fluid intake?+
Yes. Recent EFSA reviews show moderate caffeine intake does not cause net dehydration. Water, unsweetened teas, and diluted juices all contribute.
What are the signs of dehydration?+
Dark urine, thirst, headaches, fatigue, and reduced concentration. Light straw-colored urine is a good hydration indicator.
Can you drink too much water?+
Yes, in rare cases excessive intake (several liters in a short time) can cause hyponatremia. Spreading intake throughout the day is safe.
Do athletes need more water?+
Yes. Intense exercise costs roughly 0.5–1 L of sweat per hour. For prolonged activity, electrolytes (sodium, potassium) should be added.
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Calculate Water Intake: How Much Water You Need Daily
6 min