not enough....
all the salt dehydrates you
maybe a quarter of a gallon
Water quality affects human health. One should consume clean water.
48 OUNCES
Water
Because the humidity is so low -- five percent: Antarctica is the driest continent on earth -- best practices dictate that a human consume at least two liters of water every 24 hours.
Showers/baths and clothes washing machines consume 75% of residential water
Assuming that a human lives to be 80, they will consume about 14,500 gallons of water in a lifetime. This is based on whether they drink the required amount per day. Consuming water for cooking, cleaning, and bathing has not been measured.
If you mean "How much percentage of water does a human brain have?", the answer is about 77-78%.
On average, 60%
After 72 hours that human would be severely dehydrated if not dead.
Eight to Ten 8oz servings of water www.snopes.com