Calculate your daily water intake in 4 easy steps
Proper hydration is essential for body temperature regulation, nutrient transport, and waste elimination. Your needs may vary based on activity level, climate, and health conditions.
This calculator provides general reference information and does not account for individual health conditions. Water intake needs may differ for those with specific conditions (kidney disease, heart conditions, etc.). Please consult a healthcare professional for personalized hydration advice.
Adults are generally recommended to drink 2–2.5 liters of water per day, but this varies by weight, activity level, and climate. This calculator uses 30mL per kg of body weight as a base, adjusted for activity level and climate to provide a personalized recommendation. The simplest indicator is urine color — light yellow indicates proper hydration.
Yes, the more you weigh, the more water you need. The base recommendation is approximately 30mL of water per kilogram of body weight. So a person weighing 60kg needs about 1.8L, and an 80kg person needs about 2.4L as their base daily intake.
Coffee and tea do contain water and contribute partially to overall hydration. However, since caffeine can have a diuretic effect, they are better viewed as supplementary sources rather than replacements for plain water. The recommendation from this calculator is based on pure water; when accounting for water from food and other beverages, the actual needed amount may be slightly lower.
Excessive water intake can cause hyponatremia (water intoxication), though this is very rare in everyday life. For those with kidney or heart conditions, water intake may need to be restricted, so consulting a doctor is important. More than 5 liters per day is generally not recommended without a specific medical reason.
About 60% of our body is water, and even a 1–2% decrease in body water can cause reduced concentration and fatigue. Proper hydration plays a key role in maintaining essential bodily functions such as temperature regulation, waste elimination, and joint protection.
During intense exercise, about 500–1,000 mL of water is lost through sweat per hour. In hot climates, it is recommended to drink an additional 250–750 mL beyond the base requirement. Building a habit of regularly replenishing fluids before, during, and after exercise is important.
It is important to drink before you feel thirsty. Drinking a glass of water 30 minutes before meals helps digestion and prevents overeating. The habit of drinking a glass of water on an empty stomach right after waking up helps achieve daily hydration goals and activates metabolism.