Getting the proper amount of water is extremely important as every cell, tissue, and organ in our bodies needs water. When you don't get enough water, every cell of your body is affected. When you sweat, you lose a lot of electrolytes, including sodium, potassium and chloride, which are essential to your body's functions. The basic equation for determining this is by dividing your body weight in half. So, if you weigh 200 pounds, you would need 100 ounces of water per day if you're not doing anything strenuous.