Daily Water Intake Calculator
Estimate a daily water intake target from your body weight and activity.
Roughly how much to drink
Daily fluid needs vary with body size, activity, climate and diet, and this gives a rough target from your weight and activity level as a starting reference. It is a guide to hydration rather than a strict prescription, since the right amount is quite individual.
Enter your weight and activity to see an estimated target.
Listen to your body, not just a number
Hydration advice is often over-precise, but the honest picture is simpler than the rules suggest. Your needs rise with heat, exercise and altitude, and a good chunk of fluid comes from food and other drinks, not just water. Rather than fixating on hitting an exact figure, thirst and the colour of your urine are practical everyday guides — pale is generally well-hydrated. Both too little and, less commonly, far too much water can be a problem, so the aim is sensible balance, not forcing down a target. This is general information, not medical advice; if you have a health condition affecting fluid needs, follow your professional's guidance.
Frequently asked questions
How much water should I drink a day?
It depends on your size, activity, climate and diet, so a target is only a rough guide. Thirst and pale urine are practical everyday indicators.
Does all my fluid have to be water?
No — food and other drinks contribute a good share of your daily fluid, so the water target is not the whole story.
Is this medical advice?
No — it is general information. If a health condition affects your fluid needs, follow your professional's guidance rather than a generic target.