Water Intake Calculator
Find out how much water you should drink daily based on your weight, activity level, and climate.
How Much Water Do You Really Need?
The old "8 glasses a day" rule is a rough estimate. More accurate: drink 0.5 to 1 ounce per pound of body weight. A 160 lb person needs 80-160 oz/day depending on activity.
Signs You're Not Drinking Enough
- Dark yellow urine (should be pale yellow)
- Fatigue and low energy
- Headaches
- Dry skin and lips
- Constipation
- Dizziness
Water vs Other Beverages
Plain water is best but all fluids count toward hydration: tea, coffee, milk, and even caffeinated beverages contribute. About 20% of water intake comes from food (especially fruits and vegetables).
When to Drink More
- During and after exercise
- Hot or humid weather
- Illness (fever, vomiting, diarrhea)
- Pregnancy and breastfeeding
- High altitude
Your Daily Water Needs
Minimum
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Recommended
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Active Days
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Glasses (8oz each)
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