💧Water intake calculator
Estimate how much water you may need to drink a day.
Estimates for healthy adults. Not medical advice — if you are pregnant, breastfeeding, under 18 or have a medical condition, ask your doctor or dietitian.
How it is calculated
The calculator starts from about 30 ml of water per kg of body weight and adds about 500 ml for 30–60 minutes of exercise (or 1,000 ml for more than an hour) and 500 ml in hot or humid weather. The result is kept between 1.5 and 4.5 litres.
For comparison, EFSA suggests an adequate total water intake of about 2.0 L a day for women and 2.5 L for men from drinks and food together; roughly 20% usually comes from food.
Thirst, urine colour and the weather are good everyday guides. If you have kidney, heart or other medical conditions, follow your doctor's advice on fluids.
Questions
Do tea, coffee and food count?
Yes. All drinks count, and food — especially fruit, vegetables and soups — supplies around a fifth of your fluid.
Is it possible to drink too much water?
Yes, though it is rare. Drinking very large amounts in a short time can dilute blood sodium. Spread your drinks through the day.
Do I need more water when I am ill or pregnant?
Often yes, for example during fever, vomiting or diarrhoea, pregnancy and breastfeeding. Ask your doctor for personal advice.
How can I tell if I am drinking enough?
Pale yellow urine and rarely feeling thirsty are good signs.
Track it every day with Me Nutrition
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