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Water Intake Calculator - Daily Water Needs

Free water intake calculator to find how much water you should drink daily. Personalized water amount based on weight, activity, and climate.

Water Intake Calculator

Find out how much water you should drink daily

kg

Your body weight determines your base water needs.

Physical activity increases water loss through sweating.

Hot weather increases sweating and requires more water.

Men generally need slightly more water than women.

Your Water Needs

Enter your values to see results

and click the "Calculate" button

Why Daily Water Intake Matters

Water makes up about 60% of our body and is critical for all vital functions. Nutrient transport, toxin elimination, body temperature regulation, joint lubrication, and cognitive functions are just some benefits water provides. Even mild dehydration can cause fatigue, headaches, and concentration loss. Your daily water needs vary based on weight, activity, climate, and special conditions.

How to Use This Calculator

  1. Enter your weight
  2. Select your activity level
  3. Choose your climate/weather
  4. Select gender and any special conditions
  5. Click Calculate to see your daily water needs

Water Calculation

Base: 30-35ml per kg body weight

Adjusted for activity level, climate, and special conditions.

Frequently Asked Questions

Is the 8 glasses of water rule correct?
8 glasses (2 liters) is a general guideline but not right for everyone. Water needs vary by weight, activity, and climate. A 50kg sedentary person and 90kg athlete don't need the same amount.
Do tea and coffee count as water?
Yes, they contribute to water intake. However, caffeine is a mild diuretic so not as effective as plain water. Up to 400mg caffeine daily (3-4 cups coffee) generally isn't a problem.
Does drinking water during meals harm digestion?
No, this is a myth. Reasonable water during meals doesn't impair digestion, it actually helps food breakdown. Just avoid excessive amounts.
If I'm not thirsty, am I getting enough water?
Thirst is already a sign of mild dehydration. It's better to drink water regularly before feeling thirsty. Monitor urine color - light yellow is ideal.
Is drinking too much water harmful?
Yes, excessive water (hyponatremia) dilutes sodium in blood and can be dangerous. Don't exceed 6-7 liters daily. Drinking too much too quickly (more than 1 liter per hour) is risky.
Should I drink water before or after exercise?
Both. Drink 500ml 2-3 hours before exercise, 250ml 20-30 minutes before, 150-250ml every 15-20 minutes during, and enough afterward to replace losses.

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