Read about how many glasses of water humans should drink every day.
The experts recommend humans drink six to eight glasses of water every day as a safe amount. However, active persons may need 15 glasses, while small and inactive persons only need two glasses.
In the course of a day, the body uses between 1 1/2 and three quarts (1.4 to 2.8 liters) of water just in breathing, sweating and releasing waste fluids. Less than a quart is supplied by food. So, the the rest should be from about six glasses of liquid a day.