Water Intake Calculator
Calculate your recommended daily water intake based on your weight, activity level, and climate, instantly in your browser.
How to use the Water Intake Calculator
- Enter your body weight in kilograms.
- Choose your activity level.
- Choose your climate: temperate or hot and humid.
- Click Run to see your recommended daily water intake in liters, cups and fluid ounces.
How the Water Intake Calculator works
The calculator starts from a common guideline of about 33 ml of water per kilogram of body weight per day, so a 70 kg adult needs roughly 2.3 liters. It then adds extra fluid to replace water lost through sweat: 0.35 liters for moderate activity or 0.7 liters if you're active most days, plus another 0.5 liters in a hot or humid climate.
The result is a guide for drinking water and other fluids. Food, especially fruit and vegetables, provides additional water, and needs rise during illness, pregnancy and breastfeeding. Pale yellow urine is a simple everyday sign that you're drinking enough.
Frequently asked questions
- Is this water intake calculator free?
- Yes. Calculate your recommended water intake at no cost, with no account required.
- How is water intake calculated?
- A base of 33 ml per kg of body weight is used, with additional amounts added for higher activity levels and hot climates.
- Does this include water from food?
- No. This estimates recommended fluid intake from drinking water; you also get water from food and other beverages.