About the Water Intake Calculator
This gives a rough daily fluid guideline from body weight and exercise. Real needs vary with climate, health, and the water you get from food and other drinks — thirst and urine color are useful everyday cues.
How it’s calculated
About 35 ml of fluid per kilogram of body weight, plus roughly 350 ml per 30 minutes of exercise.
Example calculation
A 70 kg person doing 30 minutes of exercise gets a guideline of about 2.8 litres (around 12 cups) a day.
Frequently asked questions
Does all fluid count, or just water?
Most fluids and water-rich foods contribute to hydration, so you don't need to drink this entire amount as plain water. It's a total-fluid guideline.
Can you drink too much water?
Yes, in rare cases very high intake can be harmful. Some medical conditions also require fluid limits — follow a doctor's advice over any general estimate.
This tool provides a general, informational estimate only. It is not medical advice and cannot diagnose, treat, or replace guidance from a qualified healthcare professional. Individual health depends on many factors this estimate does not capture. If you have questions about your health, talk to a doctor.