Estimate your daily water needs from your body weight, how much you exercise and how hot your climate is. Get a clear target in litres, fluid ounces and glasses.
How to use the Water Intake Calculator
- Enter your weight in kg or lb.
- Enter your daily exercise time in minutes.
- Choose your climate and whether you are pregnant or breastfeeding.
- See your recommended daily water intake.
How the estimate is calculated
A common baseline is about 35 ml of water per kg of body weight per day. We add roughly 350 ml for every 30 minutes of exercise, 10–20% for hot or humid climates, and extra for pregnancy (+300 ml) or breastfeeding (+700 ml).
About 20% of daily water usually comes from food, so the drinking target is a little lower than total water needs.
Frequently asked questions
Do other drinks count?
Yes. Tea, coffee, milk and water-rich foods all contribute to hydration.
Can you drink too much water?
Yes. Drinking very large amounts quickly can cause hyponatremia. Spread intake through the day and follow thirst.