The amount of water you should drink daily depends on several factors including your sex, body weight, activity level, climate, and health status. General guidelines from reputable sources are as follows:
- For healthy adults living in temperate climates, the U.S. National Academies of Sciences, Engineering, and Medicine recommends about 3.7 liters (15.5 cups) of fluids per day for men and about 2.7 liters (11.5 cups) for women. This includes all fluids consumed, including water, other beverages, and moisture from food
- The NHS in the UK suggests aiming for 6 to 8 cups (about 1.9 liters) of fluids daily, including water, milk, and other drinks
- Some experts recommend calculating water intake based on body weight, such as about 35 ml per kilogram of body weight. For example, a person weighing 72 kg (159 lbs) should aim for around 2.5 liters per day, while someone weighing 85 kg (188 lbs) might need about 3 liters
- Your needs increase if you live in hot or humid environments, are physically active, pregnant or breastfeeding, or have certain health conditions
- The traditional "8 glasses a day" rule (about 2 liters) is a simple guideline but may not be sufficient or necessary for everyone; thirst and individual circumstances are better guides
In summary, a typical adult man should aim for around 3 to 3.7 liters of fluids daily, and a woman about 2.7 liters, adjusting for personal factors such as activity and environment. Drinking consistently throughout the day and including fluids from all sources helps maintain proper hydration
