There is no single right amount of water for everyone. This calculator gives a rough starting estimate based on your body weight, how much you exercise and the climate you live in.
Fill in the form to see your estimate. Nothing you enter is stored or sent anywhere.
Estimates only, based on population equations. Not medical advice. If you are pregnant, under 18, have a medical condition or take medication that affects weight or appetite, check with a qualified healthcare professional.
How the estimate works
It uses a common rule of thumb of about 33 ml per kg of body weight, adds roughly 350 ml for every 30 minutes of exercise and 500 ml for hot or humid weather. Because about a fifth of daily water typically comes from food, the headline figure shows fluid from drinks.
Signs you are drinking enough
- You rarely feel very thirsty.
- Your urine is pale yellow most of the day.
- You are not getting headaches or feeling light-headed during exercise.
Does water help with weight loss?
Water has no calories, so swapping sugary drinks for water is one of the easiest ways to cut calories. Drinking a glass before meals may also help some people feel fuller. Tea, coffee, milk and other drinks all count towards your fluid intake.