Water Intake Calculator
Calculate your recommended daily water intake based on your weight and activity level. Results shown in liters, cups, and fluid ounces.
This calculator is for informational purposes only and should not replace professional medical advice.
How It Works
This calculator estimates your daily water needs using a weight-based formula adjusted for activity level.
Base formula: 35 mL per kilogram of body weight per day.
Activity adjustments:
- Sedentary: base × 1.0
- Moderately active: base × 1.2
- Active: base × 1.4
- Very active: base × 1.6
Frequently Asked Questions
How much water should I drink per day?
A general guideline is about 35 mL per kilogram of body weight per day, adjusted for activity level. For an average 70 kg adult, that's about 2.5 liters. Active individuals need more to replace fluids lost through sweat.
Does coffee or tea count toward water intake?
Yes, beverages like coffee, tea, and even foods with high water content (fruits, vegetables, soups) contribute to your daily hydration. However, water remains the best choice for hydration as it has no calories or additives.
How do I know if I'm drinking enough water?
Good indicators of proper hydration include pale yellow urine, infrequent thirst, and consistent energy levels. Dark yellow urine, dry mouth, and fatigue can be signs of dehydration.
Should I drink more water in hot weather?
Yes, you should increase your water intake in hot or humid conditions, at high altitudes, or when you're ill (especially with fever, vomiting, or diarrhea). This calculator provides a baseline — adjust up as needed.