Water Intake Calculator
Find out how much water you should drink per day based on your weight and activity level.
Input
Enter your weight to estimate your daily water intake.
The Water Intake Calculator estimates how much water you should aim to drink each day based on your body weight and how active you are. It is a helpful starting point when you want a simple daily hydration goal rather than guessing.
How to use the Water Intake Calculator
- Enter your body weight.
- Add your typical amount of daily exercise or activity.
- Submit to see your suggested daily water target.
- Adjust upward in hot weather or during heavy exercise.
Frequently asked questions
- How is the water target calculated?
- A common rule estimates about 0.033 litres of water per kilogram of body weight, plus extra for exercise. For a 70 kg person that base is 70 x 0.033 = about 2.3 litres per day before adding any activity allowance.
- Does food and other drinks count toward this?
- Yes. Foods like fruit and soup and beverages such as tea contribute to your fluids, so you usually do not need to drink the full amount as plain water.
- How do I know if I am drinking enough?
- Pale, light yellow urine and rarely feeling thirsty are good general signs of adequate hydration, while dark urine can suggest you need more fluids.
- Is this hydration amount medical advice?
- No. It is an estimate for general information only and not medical advice. People with kidney, heart, or other conditions should follow the fluid guidance of their doctor.