How much water should I drink daily?

A standard rule is 35 ml of water per kg of body weight. For a 70 kg person that is 2.45 litres per day. Active people and those in hot climates need 20–30% more.

Does activity level affect water intake?

Yes. Higher activity increases water needs by 20–40% because your body loses more fluids through sweat during exercise.

Can I drink too much water?

Yes, overhydration (hyponatremia) is possible but rare. It usually only occurs in endurance athletes who drink excessive amounts. For most people, drinking 2–3 litres a day is perfectly safe.

Does tea and coffee count as water intake?

Partially. Tea, coffee and other beverages contribute to hydration, but plain water is best. Caffeinated drinks have a mild diuretic effect, so pure water should be your primary source.

Home›Calculators›Water Intake

💧 Daily Water Intake Calculator

Calculate how much water you should drink every day based on your weight, activity, and climate.

Body Weight (kg)

Activity Level

Climate

💡 General rule: 35 ml per kg body weight. Increase by 20-30% for hot climates and exercise.

How Much Water Should You Drink Daily?

Water is essential for every cell, tissue, and organ in your body. It regulates body temperature, transports nutrients, flushes waste, cushions joints, and supports digestion. Yet most Indians are chronically dehydrated — studies suggest up to 75% of people don't drink enough water daily.

The commonly cited "8 glasses a day" (2 litres) is an oversimplification. Your actual water needs depend on your body weight, physical activity, climate, and overall health. This calculator uses the clinically validated 35ml per kg body weight baseline and adjusts for your lifestyle.

Water Intake Formula

Base Intake = Body Weight (kg) × 35 ml
Activity Adjustment: Add 500ml (moderate) or 1000ml (intense exercise)
Climate Adjustment: Add 300–500ml in hot or humid conditions

Example Calculation

Person: 70 kg | Moderately Active | Hot Climate

Base: 70 × 35 ml = 2,450 ml
Activity (moderate): + 500 ml
Climate (hot): + 300 ml
Total Daily Requirement: ~3,250 ml (3.25 litres)
That's approximately 13 glasses of 250ml each.

Signs of Dehydration to Watch For

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Urine Colour Check

The easiest hydration test: pale yellow = well hydrated. Dark yellow = mildly dehydrated. Amber/brown = severely dehydrated. Drink water immediately.

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Headaches

The brain is 75% water. Even mild dehydration (1–2% fluid loss) causes headaches, reduced concentration, and fatigue. Drink a glass of water before reaching for pain relievers.

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Food Counts Too

20–30% of your daily water intake comes from food. Cucumbers, watermelon, tomatoes, and oranges are 90%+ water. Eating water-rich fruits reduces how much you need to drink.

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Drink Schedule

Don't wait until thirsty — thirst means you're already 1–2% dehydrated. Start with 1 glass on waking, 1 glass before each meal, 1 glass after exercise, and 1 glass before bed.

Water and Weight Loss

Drinking 500ml of water 30 minutes before meals has been shown in studies to reduce calorie intake by 13% in middle-aged and older adults. Water boosts metabolism by 24–30% for 1–1.5 hours after drinking. Starting your day with 2 glasses of water before breakfast is one of the simplest, free weight management habits.

Electrolytes matter too: If you exercise heavily or sweat a lot, plain water alone isn't enough. Include sources of sodium, potassium, and magnesium — coconut water, buttermilk, or electrolyte drinks help maintain the balance your body needs.