Use This Formula To Calculate How Much Water You Need

"I try to take care of myself, drinking at least a gallon of water with lemon a day and making sure to take my vitamins,” Queen Bey once told Vogue magazine.  But is that really necessary? As Nicole Richie once said, "Drinking 8 glasses of water is so 90's." Instead, use this more precise formula that Kerry told us in this recent feature for Charlotte’s…