Yep. 100. Per. Day.
Up to 60% of the human adult body is water.
According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%. Blood is 92%.
READ THIS: everything mandatory for living is about 3/4 water thus, the water you drink FEEDS it. Now, this is super layman's but you get the idea.
Do you ever feel puffy? That's not bc of the sushi you ate last night...it's bc your body is storing water. Answer: drink more water! Seems counterintuitive right? I get it. However, the more water you drink the better your system flushes so you won't get puffy again. Promise!
Now, the climate you live in, the amount of salt, sugar, coffee, and booze you drink will create the need for water.
Your minimum water in take is 10-12, 8oz glasses...if you don't drink any caffeine and booze and don't eat salt or sugar. Since we all know we ALL do at least one of those...ahem: drink 100oz. It won't hurt you. Yes, you could drink too much but I challenge you to challenge that. #goodluck.
By the way, water is plain water. Not juice water, caffeine water, sugar water (you get my point). You may put in lemon or lime. REAL fruits and veggies count about 20-30% of that BUT! If you're doing your best to lose weight: fruit ALSO COUNTS AS CALORIES. #jussayin
This the only body you get, take care of it!
Great article on water: