Water Intake Calculator
Calculate your recommended daily water intake in liters, glasses, and ounces based on your body weight, exercise level, and climate.
Body Weight
Exercise Level
Climate
Recommended Daily Water Intake
2.8L
Glasses (250ml each)
11 glasses
Ounces
95 fl oz
How the Water Intake Calculator Works
This calculator estimates your recommended daily water intake using the common rule of thumb of 35 ml of water per kg of body weight, then adds extra for exercise (which increases fluid loss through sweat) and hot or humid climates.
How to Use It
- Enter your body weight in kg or lbs.
- Select your typical daily exercise level.
- Select your climate to see your recommended daily water intake in liters, glasses, and ounces.
Example
A 70kg person with light daily exercise in a normal climate needs roughly 2.8L per day — about 11 glasses of water.
Common Use Cases
- Setting a daily hydration target to track in a water-reminder app.
- Adjusting fluid intake for a workout routine or a hot climate.
- Getting a quick, personalized answer to "how much water should I drink a day?"
FAQs
Is "8 glasses a day" accurate?
The "8x8 rule" (eight 8-ounce glasses, about 2 liters) is a simple, memorable guideline, but individual needs vary a lot with body size, activity, and climate — which is why this calculator scales the target to your own weight instead of using one fixed number for everyone.
Does this include water from food and other drinks?
No — this estimate is for direct water/fluid intake. In practice, food (especially fruits and vegetables) and other beverages also contribute to total hydration, so your actual need for plain water may be somewhat lower depending on your diet.
Can I drink too much water?
Yes — drinking far more water than your body needs in a short time can lead to a dangerous condition called hyponatremia (low blood sodium). This calculator gives a general daily estimate, not medical advice; people with kidney, heart, or liver conditions should follow fluid guidance from their doctor instead.