I found this so useful! I never saw a chart to explain this. What I have read is general rules of how much water we should drink. The very interesting part of this is I only feel comfortable when I drink the very amount listed for my weight. I have tried following the rules for body building, which is double the amount I should drink. It left me feeling ill. So most of the time, I keep saying I am not getting enough water. It turns out I am getting just the right amount by listening to my body. It does make sense that my fluid needs would not match that of a 200 lb man, just as my calorie intake is different from his as well. Yet, this is the first time I ran across a chart with specific guidelines.