How Much Water a Day Should Someone Drink?

Depending on what you read and who you ask, the amount of water you need to consume per day is different. One source may tell you six to eight glasses, while another may tell you just six cups. The fact of the matter is that how much you should drink every day is different for everyone. There are several approaches to drinking water that may help you decide how much you should drink. None of these approaches is right or wrong; you just have to choose the one that best fits your lifestyle and need for fluids.

Replacing Lost Water

• If you take the approach that you need to replace the water that you lose through sweat, urine, breathing and even bowel movements, you may find that drinking the right amount of water is easier for you than drinking an arbitrary amount of water that has no science behind it. Based on the fact that you lose about six cups of water a day through urine and another liter through breathing and sweating, if you consume about two liters (or about eight cups) of water every day, you should be able to replace all of the water you lost and maintain a good level of health.

Institute of Medicine Guidelines

• If you like to follow guidelines given by a true medical authority, you may want to follow the guidelines for water consumption provided by the Institute of Medicine. The guidelines state that men should try to drink three liters (or about 13 cups) of water each day and women should consume at least nine cups per day. These guidelines are not too far off from the water replacement approach to drinking enough water every day.

Eight by Eight Rule

• Many people have followed the eight by eight rule for years. This is a guideline to water consumption that states that you should drink eight 8-ounce glasses of water per day. Depending on who you talk to, the eight glasses need to be water, but some people bend this rule a bit and state that the eight 8-ounce glasses can be any noncaffeinated fluid or beverage.