Daily Water Intake Calculator

The calculator multiplies your body weight in kilograms by 35 ml — the standard clinical recommendation of 35 ml of water per kilogram of body weight per day. The result in milliliters is then divided by 1,000 to convert to liters. For example, a 70 kg person: 70 × 35 = 2,450 ml = 2.45 liters per day. A 90 kg person: 90 × 35 = 3,150 ml = 3.15 liters. This formula is widely cited in clinical nutrition guidelines and is a more personalized alternative to the generic eight-glasses rule, which treats every adult the same regardless of body size. This recommendation represents total fluid intake from all beverage sources; approximately 20% of daily water needs are typically covered by water content in food, so the actual drinking target can be adjusted downward slightly for those with a high-vegetable, high-fruit diet.