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Water Intake Calculator

Enter your weight and select your activity level to get a recommended daily water intake.

Your details

Live calculator output

Enter your weight and activity level to see your recommendation.

How it works

The calculator multiplies your body weight by an activity factor to estimate daily water needs. Sedentary individuals need about 30 ml per kg of body weight, while very active people need up to 45 ml/kg. The result accounts for water from all sources including food and beverages. About 20% of daily water intake typically comes from food, so actual drinking water needed is slightly less than the total shown.

Practical example

A 70 kg person with moderate activity: 70 × 35 = 2,450 ml (about 2.5 liters or 10 glasses of water per day). A very active person at the same weight: 70 × 45 = 3,150 ml (about 3.2 liters or 13 glasses). In hot weather, add 500-1,000 ml to these estimates.

Frequently asked questions

Reusable FAQ content keeps each calculator page richer for users and search engines.

Is this just plain water?

Total fluid intake includes water from food and other beverages, not just plain water.

Should I drink more in hot weather?

Yes. Heat, humidity, and altitude all increase your fluid needs.

Can I drink too much water?

Rarely, but overhydration is possible. Follow your thirst and these guidelines as a baseline.

Does coffee count toward water intake?

Yes. While caffeine is a mild diuretic, the net hydration from coffee and tea is positive. They count toward your daily fluid total.

How do I know if I am drinking enough?

The best indicator is urine color. Pale straw yellow means well-hydrated. Dark yellow or amber suggests you need to drink more.

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