Water Intake Calculator

Suggested daily water intake.

Estimate a suggested daily water intake based on your weight and exercise minutes.

How it works

A baseline amount is estimated from your body weight, and extra water is added for the minutes you exercise, to replace fluid lost through sweat.

When it helps

Gives a simple daily target to aim for if you tend to forget to drink.

How the estimate is calculated

The baseline is 0.033 liters (33 ml) per kilogram of body weight. On top of that, the tool adds 0.35 liters for every 30 minutes of exercise. For someone weighing 70 kg who exercises for an hour, that's 70 × 0.033 = 2.31 liters plus 0.7 liters, or about 3 liters a day.

The result is total fluid, not only plain water. Tea, coffee, milk, soup and water-rich foods all contribute.

Signs and adjustments

Pale yellow urine is a simple sign that you're drinking enough; dark urine and thirst suggest you need more. Drink more in hot weather, at high altitude, during illness with fever, and while breastfeeding.

More isn't always better: drinking very large amounts in a short time can be harmful. People with heart or kidney conditions may be told to limit fluids, so follow medical advice over this general estimate.

Frequently asked questions

Does food count?

Yes. A fair amount of daily water comes from food, especially fruit and vegetables.

Should everyone follow this number?

No. Needs vary with climate, health and medical conditions. Follow your doctor's advice if you've been given specific guidance.

How can I remember to drink more?

Keep a refillable bottle within reach, drink a glass with each meal, and set a few reminders during the day.

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