Water intake It's common knolwedge that if you want to be healthy you should drink 8 glasses of water a day. But how much water is that? Currently drinking around 1.5L a day and on the weekend i will be upping it to 3L because i have a grading to go to on monday and everyone is telling me to stay hydrated. i've done a few google searches but everything is giving me answers in ounces, and will only tell me how much to drink if i've excercised that day. So how much should i drink daily (in liters) to stay adequately hydrated?