How much water should be drink in a day?

Drink when thirsty: There is no particular amount of water needed by healthy persons, and no need to keep track of how much you drink. Drink water or other fluids as needed to satisfy your thirst. Otherwise forget it.

Water: I believe on a usual day we need 1 liter of water per day and on very very hot days we need 2 to3 liters per day, drinking too much water can lead to water intoxication which can cause confusion, seizures, coma and death due to low sodium etc.

Enough to pee: I consider it a myth to focus on a quantity of water intake when the body signals usually sort out your individual needs.You also acquire fluid content from a variety of sources. Applesauce is 95% water/fruits~80%, most vegetables~60% and there are others.You need to take in enough fluid value to pee every 6 hrs or so to stay well hydrated. Those with certain medical conditions may need more.