Find your exact daily water goal based on weight and lifestyle
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Your Daily Target
per day
How it breaks down
Formula: The baseline uses the widely-cited rule of 0.5 fl oz per pound of body weight. Activity and climate add incremental ounces based on typical sweat-loss research. These figures are general guidelines — individual needs vary. Consult a healthcare professional for medical advice.
Use our daily water intake calculator to find out exactly how much water you should drink each day. Enter your body weight in kg or lb, choose your activity level, and select your climate to get a personalised hydration target — displayed in litres, fluid ounces, glasses, and 500 ml bottles. Staying properly hydrated supports energy, focus, and overall health.
A common starting point is 0.5 fl oz (about 15 ml) of water per pound of body weight. A 70 kg (154 lb) person needs roughly 2.3 litres at rest. Activity and hot weather increase that figure by up to 500 ml or more.
No — the 8×8 rule (eight 8-oz glasses) is a rough average that does not account for body weight, exercise, or climate. Heavier or more active people need considerably more. This calculator gives you a weight-adjusted, personalised estimate.
Yes. Most non-alcoholic beverages, including coffee and tea, contribute to daily fluid intake. Food (especially fruit and vegetables) also provides a meaningful portion — roughly 20% of total hydration for many people.
The simplest indicator is urine colour — pale yellow means well-hydrated; dark yellow or amber signals dehydration. Thirst, fatigue, and headaches are also early signs you need more fluids. Use this calculator as a daily baseline target.