Water Intake Calculator
Calculate your recommended daily water intake based on your body weight, activity level, and climate conditions.
Daily Water Intake
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In Liters
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In Fluid Ounces
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Number of Glasses (250 ml)
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How to Use the Water Intake Calculator
- Choose your unit system: Select Metric (kg) or Imperial (lb).
- Enter your weight: Type your current body weight.
- Select your activity level: Choose how active you are during the week.
- Select your climate: Hot climates require more hydration.
- View your results: Daily water intake in liters, fluid ounces, and glasses.
Water Intake Formula
The base recommendation is calculated as:
- Base intake: 35 ml per kg of body weight per day
- Activity adjustment: Additional 350-700 ml depending on activity level
- Climate adjustment: Additional 500 ml for hot/humid climates
This aligns with guidelines from the European Food Safety Authority (EFSA) and the National Academies of Sciences.
General Daily Water Guidelines
| Group | Recommended Intake |
|---|---|
| Adult Men | ~3.7 L (125 fl oz) |
| Adult Women | ~2.7 L (91 fl oz) |
| Active Adults | Add 0.5-1.0 L per hour of exercise |
| Hot Climate | Add 0.5-1.0 L extra daily |
Frequently Asked Questions
Does coffee count toward water intake?
Yes, moderate coffee and tea consumption can count toward your daily fluid intake. While caffeine has a mild diuretic effect, studies show that habitual coffee drinkers do not experience significant dehydration from normal consumption (up to 3-4 cups per day).
Can you drink too much water?
Yes, drinking excessive water in a short period can lead to hyponatremia (low sodium levels in the blood), which can be dangerous. Spread your intake throughout the day and listen to your body's thirst signals. Most healthy adults can safely process about 0.8-1.0 L per hour.
How do I know if I am drinking enough water?
Good indicators of proper hydration include pale yellow urine, urinating every 2-4 hours, feeling alert and energized, and not feeling thirsty often. Dark yellow urine, fatigue, headaches, and dry skin can be signs of dehydration.