FREE Calculator
Water Intake Calculator
Calculate your recommended daily water intake using the WHO 35 mL/kg guideline, adjusted for your activity level.
Water Intake Calculator
Enter your weight and activity level to find your daily hydration target
Daily Hydration Target
Enter your weight to see your water target
Daily intake in litres and ounces
Why Hydration Matters
Body Functions
Water regulates body temperature, transports nutrients, lubricates joints, and supports nearly every metabolic process.
Performance
Even mild dehydration can impair focus, endurance, and strength output during training or research work.
Guideline: The WHO-recommended baseline is 35 mL of water per kilogram of bodyweight per day.
When You Need More
- +Exercise: Add roughly 0.35 L for every 30 minutes of activity.
- +Heat & humidity: Sweat losses increase in hot environments.
- +Special conditions: Pregnancy, breastfeeding, and illness raise daily needs.
Tip: Pale-yellow urine is a simple practical indicator of adequate hydration.
Important Note
Fluid needs vary widely with climate, activity, diet, and health status. People with kidney, heart, or liver conditions should follow their healthcare provider's fluid guidance rather than a general formula.