Whats the maximum amount of water a human can drink?

water

It depends on how much waste water that person gives out (e.g sweating, urination).

the amount of water a human must drink in a day is 2 to 2.5 litres.

the amount of water a human can drink in a day is 0 to 20 litres.(it depends)

but an average human drinks 3-5 liters