> So how much fluid does the average, healthy adult living in a temperate climate need? The U.S. National Academies of Sciences, Engineering, and Medicine determined that an adequate daily fluid intake is:
> About 15.5 cups (3.7 liters) of fluids a day for men
> About 11.5 cups (2.7 liters) of fluids a day for women
> These recommendations cover fluids from water, other beverages and food. About 20% of daily fluid intake usually comes from food and the rest from drinks.
https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...
(Of course you can survive on less, but it's not ideal. A quick test to see if you're hydrated enough is to go pee. It should have the slightest tint of yellow to it. If it's clear you're drinking more than you need. source: first aid class I took)