Hint: it's not always eight glasses.
Eight, 8 oz. glasses of water a day: it’s a rule that’s been burned into our brains for years as the ideal amount of fluid to drink each day. Yet no matter how many times experts say that’s not quite accurate, many still believe “8×8” is the magic amount.
The truth: How much water you should drink each day really, truly depends on the person, Robert A. Huggins, Ph.D., of the University of Connecticut explained to Health. “Fluid needs are dynamic and need to be individualized from person to person. Factors such as sex, environmental conditions, level of heat acclimatization, exercise or work intensity, age, and even diet need to be considered.”
Read more at time.com.