Estimates only - not medical advice.
A widely used starting point: roughly half your body weight in pounds, expressed in ounces. So a 160-pound person would aim for about 80 ounces (around 2.4 liters) per day. Add roughly 12 ounces for every 30 minutes of exercise, more in heat or humidity. Pregnancy and breastfeeding also increase requirements significantly. These are estimates; individual needs vary.
Hit your goals faster with our other free fitness calculators.
About half your body weight in pounds, in ounces, as a daily baseline. Add more for exercise (roughly 12 oz per 30 minutes), heat, humidity or illness.
Most beverages contribute to daily fluid intake, including coffee and tea. Plain water is the most efficient source, but you are not obligated to drink it exclusively.
Rarely, and usually only under unusual conditions (endurance events, extreme heat). Drinking water in excess of what the kidneys can process can cause hyponatremia (low sodium), a serious condition. For ordinary daily use, thirst is a reliable enough guide.
No - a guideline.