Water Intake Calculator
Estimate how much water you should drink each day based on your weight and exercise.
A common guideline of about 33 ml per kg of body weight, plus extra for exercise. Your needs vary with climate, health and diet.
This tool is for general information only and is not medical advice. Talk to a qualified healthcare professional before making health decisions.
About the Water Intake Calculator
Staying hydrated matters, but the right amount varies from person to person. This calculator gives a practical daily target from your body weight, with a top-up for exercise.
It uses a common guideline of about 33 ml of water per kilogram of body weight, then adds extra for the minutes you exercise. Results are shown in both litres and fluid ounces.
Your climate, diet and health also affect your needs, so treat the result as a starting point. Everything is calculated in your browser.
Key features
- Target from body weight and exercise
- Results in litres and fluid ounces
- Simple, practical guideline
- Private, in-browser calculation
How to use
- 1Enter your weight.
- 2Enter your daily exercise minutes.
- 3Read your daily water target.
Frequently asked questions
- Do drinks other than water count?
- Yes, most fluids and water-rich foods contribute to hydration, though plain water is the best everyday choice.
- Can I drink too much water?
- It is rare, but drinking very large amounts in a short time can be harmful. Spread your intake across the day and drink to thirst.