Dr. B and other experts say you should drink half your weight in ounces (that’s 8 glasses of water for a 128 lb. person), with ¼ tsp. unrefined salt dissolved in water for every quart you drink.
Of course, the most important fact is that most people are chronically dehydrated and need to drink more. Clear or very light colored urine shows good hydration, and the darker your urine, the more dehydrated you are (first thing in the morning, most of us are dehydrated). Small children, the elderly, and athletes are at highest risk for dehydration, because we lose 10-15 cups of fluids daily through elimination, sweat, and breathing. The biggest factor increasing that amount is exercise–but altitude and temperature are other variables to consider.
You can, in fact, drink too much water to achieve water intoxication. This usually happens only to athletes, since your kidneys can’t process water during exercise, so competitive athletes must balance sodium and water intake. Thirteen percent of distance runners whose weight was measured before and after running and their water consumption studied, drank too much water, causing abnormally or dangerously low blood sodium levels.
Dissolve about ½ tsp. of Original Crystal Himalayan Salt (or RealSalt would be my second choice) in your water first thing in the morning to balance water and sodium levels for best hydroelectric conductivity in your body.
Get in the habit of taking your favorite reusable water bottle with you everywhere you go. Find spaces in your routine where you learn to always drink a glass or two. For instance, drink your 16 oz. water bottle all the way home from work in the car, before you prepare dinner.