The average adult generally needs about 1.5 to 2 liters of fluids per day, but this can vary depending on factors such as age, temperature, physical activity, diet, and overall health. The U.S. National Academies recommend about 3.7 liters for men and 2.7 liters for women daily, including water from all beverages and food. The traditional recommendation of eight glasses, or about 2 liters, is a reasonable goal for many people. Water intake needs can increase with exercise, hot or humid weather, health conditions, or pregnancy and breastfeeding. In summary:
- Typical range: 1.5 to 2 liters of fluid from drinks per day.
- U.S. standard recommendations: about 3.7 liters for men and 2.7 liters for women including all sources.
- Adjust intake based on activity, environment, health, and diet.
Drinking too much water (e.g., more than 8-10 liters in a short time) can overload the kidneys and cause health issues, so moderation and responding to thirst cues are important.
