Water Intake Calculator
Free daily water intake calculator — find out how many liters, ounces, and glasses of water you should drink per day based on your weight, activity level, and climate.
Add extra water during intense workouts, illness, pregnancy, or breastfeeding.
How to use Water Intake Calculator
- Enter your weight (kg or lb).
- Select your activity level.
- Choose your climate.
- See recommended daily water intake in liters, ounces, and glasses.
Frequently asked questions
How much water should I drink per day?
A common rule is 30–35 ml per kg of body weight — around 2.5 L for a 75 kg adult. Add more for exercise and hot weather.
Is 8 glasses a day right for everyone?
It is a rough guideline. Actual needs depend on weight, activity, climate, and diet. This calculator personalizes it.
Does coffee and tea count toward water intake?
Yes — despite mild diuretic effect, most fluids count. Plain water is still the best choice.
Can you drink too much water?
Yes — hyponatremia (water intoxication) is rare but possible above 4–5 L/day without electrolytes. Stick to your calculated target.
How much water for weight loss?
Drinking 500 ml 30 minutes before meals can reduce appetite. Stay at or slightly above your calculated intake.