Water Intake Calculator

This calculator estimates how much water to aim for each day from your body weight, activity level, and climate. It starts from a common guideline of about 33 ml per kilogram, then adjusts for how active you are and whether it's hot.

Active days and hot, humid weather increase the fluid you lose through sweat, so the target rises accordingly. Food and other drinks also count toward your total, so treat the number as a friendly daily goal rather than a strict rule.

Hydration and sleep are linked: mild dehydration can leave you restless with a dry mouth, while drinking too much right before bed often means waking up at night. Spacing your intake through the day supports both good hydration and undisturbed sleep.