Water Intake by Body Weight Calculator
Calculate daily water intake by body weight with personalized hydration recommendations. Find your optimal daily water needs based on weight, activity level, and environmental factors.
Quick Answer
Daily Water = Body Weight × 0.5-0.6 ounces. 150lb person = 75-90 oz daily. Add 12-24 oz per hour of exercise. Essential for hydration and health.
Calculator Preview
Daily Water: 91 oz
Liters: 2.7 L
Glasses (8oz): 11.4
Key Features
Weight-Based
Personalized by body weight
Activity Adjustment
Exercise hydration needs
Climate Factors
Weather and temperature
Health Goals
Weight loss, fitness, general
How It Works
Enter Weight
Input your body weight
Set Activity Level
Choose daily activity level
Add Climate
Select your climate zone
Calculate Needs
See personalized water intake
Why Calculate Water Intake?
Hydration Health
Maintain fluid balance
Performance
Optimize physical function
Weight Management
Support metabolism
Base Water Intake by Weight
100 lbs (45 kg)
50-75 oz daily. Minimum requirement for basic bodily functions. 6-9 glasses of water.
150 lbs (68 kg)
75-90 oz daily. Standard recommendation for average adults. 9-11 glasses of water.
200 lbs (91 kg)
100-120 oz daily. Higher needs for larger body mass. 12-15 glasses of water.
250 lbs (113 kg)
125-150 oz daily. Maximum needs for very active individuals. 15-19 glasses of water.
Activity Level Adjustments
Sedentary
Base requirement only. No additional water needed beyond basic needs. Office worker, desk job.
Lightly Active
+12 oz (1.5 glasses) daily. Light exercise 1-3 days/week. Short walks, light housework.
Moderately Active
+24 oz (3 glasses) daily. Exercise 3-5 days/week. Regular fitness routine.
Very Active
+48 oz (6 glasses) daily. Intense exercise 6-7 days/week. Athletes, physical labor.
Climate and Temperature Factors
Cold Climate (Under 60°F)
Base requirement. May slightly increase due to increased urine output.
Temperate Climate (60-80°F)
Base requirement. No adjustment needed for moderate temperatures.
Exercise in Heat
+8-16 oz per hour of intense exercise. Critical for preventing dehydration.
Calculate Your Water Needs
Find personalized hydration recommendations for optimal health and performance
Use Full CalculatorFrequently Asked Questions
Can I drink too much water?
Yes, water intoxication is possible, though rare. Signs include confusion, headache, nausea, and in severe cases, seizures. Most healthy adults can safely handle 1-1.5 gallons per day.
Does coffee and tea count toward water intake?
Yes, but caffeinated beverages have mild diuretic effects. For every cup of coffee, drink an additional 1-2 glasses of water to compensate.
How do I know if I'm properly hydrated?
Check your urine color - pale yellow indicates good hydration. Dark yellow means you need more water. Clear urine might mean over-hydration.
Should I drink water before meals?
Yes, drinking water 30 minutes before meals can aid digestion and help control appetite. Don't drink large amounts immediately before eating.