💧 Water Intake Calculator
How much water you should drink daily
Written by Albert Mateos · Founder & Editor
Last reviewed: May 2, 2026
How it works
Find out exactly how much water you should drink daily based on your body weight, activity level, and climate. Get your recommendation in liters and glasses. Staying properly hydrated improves energy, focus, digestion, and exercise performance.
How to Use This Calculator
- Enter your weight in kilograms or pounds.
- Select your activity level and daily exercise duration.
- Adjust for climate if you live or train in hot conditions.
- Review your recommended daily water intake in liters or ounces.
- Spread intake evenly across the day rather than consuming it in large bursts.
Example
Inputs: 75 kg adult, moderate activity, 60 minutes of exercise per day.
Result: Recommended 2.8 liters (95 oz) of water per day.
What it means: This covers baseline hydration plus additional fluid loss from exercise. Urine should be pale yellow throughout the day.
Tips
- Urine color is the most practical hydration marker. Pale straw means you're well hydrated. Dark yellow means drink more.
- Add 500-750 ml for every hour of intense exercise, and up to an extra liter in hot or humid conditions.
- Coffee and tea count toward total fluid intake. The 'caffeine dehydrates you' claim is outdated at normal consumption levels.
- Drinking too much too fast can cause hyponatremia (low sodium). Sip consistently rather than chugging large volumes.
- Foods like fruits, vegetables, soups, and yogurt contribute roughly 20% of daily fluid intake. You don't need to drink it all.
Learn More
Frequently Asked Questions
- How much water should I drink per day?
- A common baseline is about 33 mL per kilogram of body weight, which works out to roughly 2.3 liters for a 70 kg person. However, your actual needs increase with physical activity, hot weather, and high altitude. This calculator adjusts for those factors to give you a personalized recommendation.
- Does coffee or tea count toward my daily water intake?
- Yes, coffee and tea do contribute to your total fluid intake despite being mild diuretics. Studies show the fluid they provide more than offsets any diuretic effect at normal consumption levels. That said, plain water remains the best choice for staying consistently hydrated throughout the day.
- Can you drink too much water?
- Yes, overhydration can lead to a condition called hyponatremia, where sodium levels in the blood become dangerously low. This is rare in everyday life but can occur during prolonged intense exercise if you drink excessively without replenishing electrolytes. Drink to thirst and use this calculator as a general guide, not an absolute rule.
Authoritative resources
We recommend these external sources for further reading from recognized health organizations and peer-reviewed literature:
- Dietary Reference Intakes for Water — NIH / IOM
- Water and hydration: physiology — CDC
Scientific References
This calculator is based on peer-reviewed research and established health guidelines:
- Institute of Medicine (IOM). Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. National Academies Press. 2005.