Do coffee and tea count?

Yes - modern research shows caffeinated drinks contribute net positive hydration. Food provides about 20% of daily water.

Water Intake Counter & Intake Calculator

Q: How much water should I drink daily?

30-35 ml per kg of body weight is a common rule. ~2L for a 60kg adult. Add 0.5-1L per hour of exercise.

Q: What are signs of dehydration?

Dark yellow urine, thirst, headache, fatigue, dizziness. Pale-straw urine indicates good hydration.

Q: Can you drink too much water?

Yes - hyponatraemia is rare but dangerous, mostly in endurance athletes drinking large volumes of plain water without electrolytes.

Weight

Activity Level

Climate

Preferred Output Unit

About the Water Intake Calculator

Daily water intake recommendations are based on your body weight, activity level, and climate — because every person's hydration needs differ. Proper hydration supports kidney function, body temperature regulation, nutrient transport, and cognitive performance. This calculator gives you a personalised daily water target rather than the generic "8 glasses a day" advice.

How to Use

Enter your body weight in kg or lbs
Select your typical daily activity level
Choose your climate (cool, warm, or hot and humid)
Select your preferred output unit, then click Calculate to see your daily water target

Formula Used

Base = Weight (kg) × 33 mL/day

Activity Add-on:
Light: +350 mL | Moderate: +700 mL
Very Active: +1,000 mL | Athlete: +1,500 mL

Climate Add-on:
Warm: +250 mL | Hot & Humid: +500 mL

Total = Base + Activity + Climate

Add an extra 300–500 mL for every 30 minutes of vigorous exercise. Hot climates and illness also increase needs significantly.

Understanding Your Results

Daily Water Need Your total recommended intake in your chosen unit — spread this evenly throughout the day rather than drinking large amounts at once.

Exercise Adjustment The extra fluid added for your activity level and climate. Sweat increases fluid loss significantly — drink before, during, and after exercise.

Minimum Intake Bare minimum for healthy kidney function is approximately 1,500 mL/day (6 glasses). Below this level, kidney stones and urinary tract issues become more likely.

Frequently Asked Questions

How much water should I drink daily?

A common rule is 30–35 ml per kg of body weight (≈ 2 L for a 60 kg adult, 2.8 L for an 80 kg adult). Add 0.5–1 L for each hour of exercise and more in hot/humid climates. The "8 glasses (2 L)" rule works as a baseline for most adults.

Does coffee, tea or other drinks count toward water intake?

Yes — modern research shows that even caffeinated drinks contribute net positive hydration in habitual users. Milk, soups, fruits and vegetables also count. About 20% of total daily water typically comes from food.

What are signs of dehydration?

Dark yellow urine, infrequent urination, thirst, headache, dry mouth, fatigue, dizziness on standing. Pale-straw-coloured urine is a quick visual indicator that you're well hydrated.

Can you drink too much water?

Yes — over-hydration (hyponatraemia) is rare but dangerous, mostly seen in endurance athletes drinking large volumes of plain water without electrolytes. Healthy adults rarely exceed safe limits in everyday life.

Medical Disclaimer

This calculator provides estimates for general informational purposes only. Results are not a substitute for professional medical advice. Consult a qualified healthcare provider for personalised guidance.

Share: Suggest a Calculator