Well, it depends. The human body is about 60% water (even your bones are about 1/3 water!),. So keeping our bodies topped up with water is essential. Water does everything from keeping our cells functioning properly, to regulating body temp, to flushing out waste, to absorbing shock and lubricating joints.  

But we lose some of that water content every day just by being—breathing, sweating, going to the toilet. Figuring out how much you need really depends on how you live your life—how much activity are you doing, what you eat, etc. The US National Academies of Sciences, Engineering, and Medicine recommend 15.5 cups (3.7 liters) of fluids per day for men and 11.5 cups (2.7 liters) for women—assuming you’re an average, healthy adult living in a temperate climate. That fluid intake is more than just water—about 20% of it can come from food, and 80% from beverages.  

It’s best to listen to your body. If you feel thirsty, drink water. If your urine skews to the golden end of the yellow spectrum, drink water. If you’re sweaty from work or working out, drink water.  

Is it Possible to Over-Hydrate?  

It’s rare and typically only happens to athletes, but it is possible to take in too much water. When that happens, your kidneys can’t flush the water out fast enough and the minerals your body depends on to function normally get diluted, which causes a lot of problems. It’s called hyponatremia and it can be life-threatening.