Water Intake Calculator
Free online Water Intake Calculator.
Calculator
How to Use
- Enter the required values
- Click Calculate to see the result
- Review the detailed output
Formula
Daily Water = Weight(lbs) / 2 oz (general). Add 12-20 oz per 30 min exercise. Adjust for climate and activity. 1 gallon = 128 oz = 3.785 liters.
Example Calculations
Based on Weight
Input: Weight: 180 lbs
Result: Daily intake: 90 oz (11.3 cups, 2.66 liters)
Active Lifestyle
Input: Weight: 150 lbs, Exercise: 1 hour/day
Result: Daily intake: 95 oz (11.9 cups, 2.81 liters)
Hot Climate
Input: Weight: 170 lbs, Hot weather, moderate activity
Result: Daily intake: 110 oz (13.75 cups, 3.25 liters)
About This Calculator
Free online water intake calculator. Calculate instantly in your browser with our easy-to-use tool. No sign-up required.
Our water intake calculator is free, easy to use, and provides instant results. All calculations are performed in your browser for privacy and speed.
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Frequently Asked Questions
How much water daily?
General: 8 glasses (64 oz / 2 liters). Individual needs vary by weight, activity, climate.
Does coffee count?
Yes, despite mild diuretic effect. Moderate caffeine (400mg/day) does not cause significant dehydration.
Exercise and water needs?
Add 12-20 oz per 30 min exercise. More in hot/humid conditions.
Signs of dehydration?
Dark urine, thirst, dry mouth, fatigue, headache. Thirst means you may already be dehydrated.
Can you drink too much water?
Yes, causing hyponatremia (low sodium). Kidneys process ~0.8-1.0 liters/hour max.