Find out exactly how much water your body needs each day — personalised for your weight, activity level, climate and fitness goal. Whether you want to calculate water intake for weight loss, muscle gain or general wellness, our free tool gives you instant, science-backed results.
Our water intake calculator starts with the scientific baseline of 35ml per kg of body weight — endorsed by the EFSA and WHO for adult daily fluid needs. We then multiply by your activity multiplier (1.0–1.65×), climate factor (1.0–1.30×) and goal modifier, giving you a precise, personalised daily target.
In hot weather your body sweats more to regulate temperature — increasing fluid loss dramatically. At temperatures above 35°C, your daily water needs can jump by 30% or more. If you're in India or any tropical region during summer, always select the Warm or Hot climate option in the calculator above.
Yes. Drinking water before meals suppresses appetite and can reduce calorie intake by up to 13%. Water also supports metabolism — adequate hydration increases your resting metabolic rate. Our water intake for weight loss calculator applies a goal-specific modifier to give you the right target for fat loss or muscle gain.