Get a general estimate of daily water intake based on your body weight and activity level. This is a starting point, not a medical recommendation.
| In cups (US, 237 ml) | – |
| In fluid ounces (US) | – |
How it works
A common starting estimate is about 33 ml of water per kilogram of body weight, plus roughly 350 ml for every 30 minutes of exercise, with a bit more in hot or humid weather. Needs vary a lot by person, climate, health and diet, so treat this as a rough guide rather than a target to hit exactly. Food, coffee and other drinks also contribute to your fluid intake.
Example
A 70 kg person doing 30 minutes of exercise needs about 70 × 33 + 350 = 2,660 ml, or roughly 2.7 liters (about 11.2 cups).
Frequently asked questions
How much water should I drink a day?
A common general guide is around 30 to 35 ml per kg of body weight, adjusted for exercise, climate and health. Ask a doctor if you have a medical condition.
Does this count coffee and tea?
This estimate is for total fluids. Many drinks count toward hydration, though very high caffeine or alcohol intake can affect this.
Can I drink too much water?
Yes, in rare cases drinking very large amounts quickly can be harmful. If you have kidney, heart or other conditions, ask a doctor for personalised advice.
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This calculator gives general estimates for information only and is not medical advice. Talk to a doctor or registered dietitian before making health changes.