Water Intake Calculator
Estimate how much water you should drink each day based on your weight, activity level, and climate.
kg
—
litres per day
—
8 oz glasses
—
millilitres
⚠ Non-medical information. This is a general hydration guideline based on simple formulas. Individual water needs vary widely depending on health, diet, pregnancy, medication, and other factors. This calculator does not replace advice from a qualified healthcare professional. If you have specific health concerns, consult a doctor or dietitian.
How to Use
- Choose your weight unit — kilograms (kg) or pounds (lb).
- Enter your weight in the selected unit.
- Select your activity level from the four options.
- Select your climate — normal or hot.
- Click "Calculate Water Intake" to see your recommended daily water intake.
When People Use This
- Planning daily hydration goals during fitness or sports training.
- Estimating water needs in hot climates or during summer months.
- Checking whether their current water consumption is roughly on track.
- General wellness and self-care planning.
Examples
Example 1
70 kg, sedentary, normal climate → 2,100 ml/day (2.1 L, ~8.9 glasses).
Example 2
70 kg, moderately active, hot climate → 3,150 ml/day (3.15 L, ~13.4 glasses).
Example 3
154 lb (70 kg), lightly active, normal climate → 2,800 ml/day (2.8 L, ~11.8 glasses).
Example 4
60 kg, very active, normal climate → 3,600 ml/day (3.6 L, ~15.2 glasses).
FAQ
- How is the water intake calculated?
- The base is 30 ml per kg of body weight for a sedentary lifestyle. Each activity level adds 10 ml/kg (light), 20 ml/kg (moderate), or 30 ml/kg (very active). A hot climate adds an extra 5 ml/kg.
- Is this amount right for everyone?
- No. Water needs depend on many factors including diet, health conditions, pregnancy, medications, and individual physiology. This is a rough guideline only.
- Do other drinks count towards this total?
- Yes, other fluids like tea, coffee, and water-rich foods all contribute to hydration. The calculator gives a total fluid target, not just plain water.
- What if I am pregnant or have a medical condition?
- Pregnancy, kidney conditions, heart conditions, and some medications significantly affect hydration needs. Always follow the guidance of your healthcare provider in these cases.
- How do I convert pounds to kilograms?
- The calculator does this automatically when you select lb — it divides your weight in pounds by 2.205 to get kilograms internally.