Water Intake Calculator: Find Your Daily Optimal Water Intake
Why is Hydration Important?
About 60-70% of the human body is composed of water, and hydration is essential for life. Water is involved in almost all bodily functions including temperature regulation, nutrient transport, waste elimination, digestion promotion, joint lubrication, and skin moisturization.
About 2-2.5 liters of water are lost daily through breathing, sweat, urine, and stool, so you need to drink enough water to replenish this. When dehydrated, various symptoms such as fatigue, headache, constipation, decreased concentration, and dry skin may occur.
Daily Recommended Water Intake
Generally, the daily recommended water intake for adults is 30-35ml per kg of body weight. For example, for a person weighing 60kg, 1,800-2,100ml (approximately 1.8-2.1 liters) is appropriate.
However, the required amount varies depending on individual activity level, environment, and health status:
- High activity level: During exercise or physical labor, a lot of water is lost through sweat, so an additional 500-1,500ml intake is needed.
- Hot weather: When temperature is high or humidity is low, sweat loss increases, so an additional 500ml or more intake is recommended.
- Breastfeeding: Breastfeeding mothers need an additional 700-1,000ml per day.
- Illness: When there is fever, vomiting, or diarrhea, more water loss occurs, so more hydration is needed.
Recognizing Dehydration Symptoms
The following symptoms may indicate insufficient water intake:
- Dark yellow or brown urine color
- Decreased urine volume and frequency
- Thirst, dry mouth
- Fatigue, lethargy
- Headache, dizziness
- Decreased skin elasticity
- Constipation
- Decreased concentration
Urine color is a good indicator of hydration status. Clear and light yellow indicates adequate hydration, while dark yellow or brown means you should increase water intake.
Proper Way to Drink Water
- Morning on empty stomach: Start your day with a glass of water right after waking up. This replenishes water lost during sleep and promotes intestinal activity.
- Before meals: Drinking water 30 minutes before meals helps prevent overeating with a feeling of fullness and aids digestion.
- Little and often: It's better to drink water little by little throughout the day rather than a lot at once. Drink 200-300ml at a time every 1-2 hours.
- Before and after exercise: Drink water 30 minutes before exercise, and replenish water every 15-20 minutes during exercise. Also drink enough after exercise to replenish lost water.
- Before feeling thirsty: Thirst is already a sign that dehydration has begun, so drink water regularly before feeling thirsty.
- Before bedtime: A glass of water 1-2 hours before sleep prevents dehydration during sleep, but drinking too close to bedtime may disrupt sleep.
Precautions When Drinking Water
Beware of Overconsumption
Drinking too much water can cause hyponatremia (water intoxication). Especially drinking a large amount in a short time is dangerous. Avoid drinking more than 4-5 liters per day, and find the right amount for you based on thirst and urine color.
If You Have Medical Conditions
If you have heart disease, kidney disease, or cirrhosis, water restriction may be necessary, so you should adjust your water intake after consulting with a doctor.
Caffeinated Beverages
Caffeinated beverages such as coffee, tea, and carbonated drinks can increase water loss through diuretic effects, so it's better to replace them with water.
Health Benefits of Hydration
- Weight management: Water has no calories and provides a feeling of fullness to suppress appetite. Drinking water before meals reduces food intake.
- Skin health: Adequate hydration maintains skin elasticity and moisture, preventing wrinkles and dryness.
- Constipation prevention: Water softens stool and facilitates bowel movements.
- Kidney function: Water dilutes and eliminates waste and toxins, preventing kidney stones and urinary tract infections.
- Headache relief: Prevents and relieves headaches caused by dehydration.
- Exercise performance: Adequate hydration prevents muscle cramps and improves exercise performance.
- Immunity: Helps circulation of blood and lymph fluid to support immune function.
Tips to Increase Water Intake
- Always carry a water bottle and drink frequently
- Set smartphone alarms (every 1-2 hours)
- Mark your water bottle to check target amount
- Add lemon, cucumber, mint, etc. to enjoy the taste
- Drink a glass of water with every meal
- Eat water-rich fruits (watermelon, orange) and vegetables (cucumber, tomato)
- Eat soup and stew dishes
- Also use warm water or herbal tea