The general recommendation for daily water intake varies by age, sex, and life stage, but a common guideline is:

• Men: about 13 cups (104 ounces) of fluids per day
• Women: about 9 cups (72 ounces) of fluids per day

These amounts include all fluids consumed, not just plain water, and also account for water obtained from food

. More specifically, the Institute of Medicine recommends approximately 3.7 liters (125 ounces) of total fluids daily for men and 2.7 liters (91 ounces) for women, which corresponds roughly to 15.5 cups for men and 11.5 cups for women

. For children, the recommendations vary by age:

• Ages 1-3: 32 ounces (4 cups)
• Ages 4-8: 40 ounces (5 cups)
• Ages 9-13: 56-64 ounces (7-8 cups)
• Ages 14-18: 64-88 ounces (8-11 cups)

Pregnant and breastfeeding women require more fluids:

• Pregnant women: about 80 ounces (10 cups) daily
• Breastfeeding women: about 104 ounces (13 cups) daily

Individual water needs can increase with physical activity, hot climates, illness, and other factors such as pregnancy or breastfeeding. About 20% of daily fluid intake usually comes from food, with the rest from beverages

. In summary, a healthy adult man should aim for roughly 100-125 ounces (12-15 cups) of fluids daily, and a healthy adult woman about 70-90 ounces (9-11 cups), adjusting based on activity, environment, and personal needs

. The "eight 8-ounce glasses" rule (64 ounces) is a simple guideline but may not be sufficient for everyone