Water Intake Calculator
Daily Water Recommendation
3.0L
Per Day
2950 ml
In Milliliters
12
Glasses (250ml)
Why Hydration Matters
Water makes up about 60% of the human body and is essential for virtually every bodily function: regulating temperature, transporting nutrients, flushing waste, lubricating joints, and supporting cognitive function. Even mild dehydration (1–2% loss of body weight) can impair concentration and physical performance.
Most adults need 2–4 liters per day, but the right amount depends on body size, activity level, climate, and health status.
Signs of Dehydration
- Dark yellow or amber-colored urine
- Dry mouth or increased thirst
- Headaches and dizziness
- Fatigue and reduced concentration
- Reduced urine output
Frequently Asked Questions
Does coffee or tea count toward hydration?
Yes, caffeinated beverages do contribute to overall hydration despite their mild diuretic effect. Research shows that moderate coffee/tea consumption counts toward daily fluid intake. However, water remains the best option.
Do I need to drink more when exercising?
Yes. During exercise, drink 150–250 ml every 15–20 minutes. For workouts lasting over 1 hour, consider a sports drink to replace electrolytes lost through sweat. The "very active" option in this calculator accounts for exercise days.
Can you drink too much water?
Yes, though rare. Overhydration (hyponatremia) occurs when you drink excessive water that dilutes sodium levels in your blood. This is most common in endurance athletes who drink plain water without electrolytes. For most people, thirst is a reliable guide.
Does food count as water intake?
Yes. About 20% of daily water intake comes from food — particularly fruits and vegetables like cucumber, watermelon, and celery. This calculator estimates total fluid needs; subtract about 500 ml if you eat a diet rich in high-water foods.
How It Works
Base recommendation is 35 ml per kg of body weight. Activity level and climate adjustments are applied on top. These are general guidelines — individual needs vary.