How Much Water Should You Drink Every Day?

For most healthy adults, somewhere between 91 and 125 ounces of total fluid per day (from all beverages and food combined) is a commonly cited general range, according to U.S. National Academies guidance — roughly 11.5 cups for women and 15.5 cups for men, including water from food, which typically supplies around 20% of total fluid intake. That's higher than the classic "eight glasses," which was always more of a rounded, easy-to-remember guideline than a precise target.

The honest answer is that there's no single number that's right for everyone. Body size, activity level, climate, and overall diet all shift the number meaningfully, which is why a personalized estimate tends to be more useful than a flat rule.

A commonly used starting formula is to drink roughly half your body weight in ounces of water per day. So a 160-pound person would aim for around 80 ounces (about 10 cups) as a baseline, before accounting for activity or heat.

The baseline above assumes a fairly average day. Several common factors push actual needs higher, sometimes by quite a lot.

Yes, mostly. Coffee and tea do have a mild diuretic effect, but modern research suggests they still contribute net positive hydration for regular drinkers, not a deficit. You don't need to "cancel out" your morning coffee with extra water.

Food also matters more than most people realize — fruits and vegetables in particular can be 85–95% water by weight. Watermelon, cucumbers, oranges, and lettuce all meaningfully contribute to daily fluid intake, which is part of why building more produce into meals supports hydration too, not just nutrition.

Rather than tracking ounces obsessively, a few simple signals can tell you most of what you need to know day to day.

It's possible, though uncommon in everyday life for most people. Drinking extremely large volumes of water in a short period can dilute sodium levels in the blood, a condition called hyponatremia — this is mostly a risk in endurance sports or extreme water-drinking challenges, not from sipping water throughout a normal day.

For the vast majority of people, the more common issue by far is drinking too little, not too much. If you have a kidney condition, heart condition, or another reason to be cautious about fluid intake, it's worth checking with a healthcare provider for personalized guidance rather than relying on general estimates like this one.