Water Intake Calculator
Calculate daily water intake
Frequently Asked Questions
How much water should I drink per day?
A common guideline is 30-35ml per kg of body weight. For a 70kg person: 2.1-2.45 liters daily. The calculator adjusts for activity level, climate, and other factors. The old "8 glasses" rule (1.9L) is a reasonable minimum for most adults.
Does exercise increase water needs?
Yes. Add 350-500ml for every 30 minutes of moderate exercise. Intense exercise or hot conditions may require 500-1000ml per 30 minutes. Weigh yourself before and after exercise — drink 1.5L for every kg lost through sweat.
Do coffee and tea count toward daily water intake?
Yes. Despite mild diuretic effects, caffeinated beverages still contribute to hydration. Studies show that regular coffee drinkers develop tolerance to the diuretic effect. However, water and herbal tea are the best hydration sources.
What are signs of dehydration?
Early signs: dark yellow urine, thirst, dry mouth, fatigue, headache. Moderate: dizziness, reduced urine output, dry skin. Severe: rapid heartbeat, confusion, fainting. Urine color is the simplest indicator — aim for pale yellow.
Can I drink too much water?
Yes, though rare. Hyponatremia (water intoxication) occurs when excessive water dilutes blood sodium below 135 mEq/L. This is most common in endurance athletes. Generally, do not exceed 1 liter per hour. The calculator sets safe upper limits.