New research has found that two litres - or eight glasses of water - a day might be too much for most people.
In fact, people can have a wide range of water intake requirements, with many only needing around 1.5 to 1.8 litres per day, according to researchers at the University of Aberdeen. Among other factors, this is because we get a good amount of water from the food that we eat.
Some 3.6 litres of water comes from food for a typical person, meaning that they need less than two litres of drinking water each day. This can vary depending on sex, age and the climate that you live in among other factors.
