I read on a health website several years back when I started my journey for better health:
Take your current body weight, divide by half, and that's your recommended daily MINIMUM of water in ounces.
At 140 pounds, I need a MINIMUM of 70 oz a day. Hope this helps.
EDIT -- On second thought, that just might be BS too. Who knows. It is how I factor it though, whether right or wrong.
** You can’t solve a problem with the same mind that created it. –Albert Einstein **