How much water and fluids should we be drinking?

How much water and fluids should we be drinking?


Water makes up about two-thirds of the weight of a healthy body. Most of the chemical reactions that happen in our cells need water in order to take place. We also needwater so that our blood can carry nutrients around the body and get rid of waste.

Water is the healthiest choice for quenching your thirst at any time. It has no calories and contains no sugars that can damage teeth. If you don't like the taste of plainwater, try sparkling water or add a slice of lemon or lime.

How much should we drink?

To stay healthy, it's important to replace the fluid we lose when we breathe, sweat or urinate.

The amount a person needs to drink to avoid getting deyhdrated will vary depending on a range of factors, including their size, the temperature and how active they are. However, as a guide, the Department of Health recommends that we should drink about 1.2 litres of fluid every day. This works out to be about six 200ml or eight 150ml glasses. 

The total amount of fluid we lose each day and need to replace is in fact greater than this – about 2.5 litres – but we get 1 litre of the fluid we need from food and the body recovers 0.3 litres from chemical reactions in our cells. The rest needs to be taken from drinks.

All drinks count, but water, is by far the healthiest. Try to avoid sugary, soft and fizzy drinks that can be high in added sugars. These can be high in calories and bad for teeth.

Signs of dehydration - One of the first signs of dehydration is feeling thirsty.

If you think you may not be getting enough fluids, check whether you have any of these other common signs of dehydration:

  • dark urine and not passing much urine when you go to the toilet
  • headaches
  • lack of energy 
  • feeling lightheaded 

Tea, coffee and caffeine 

Tea and coffee contain caffeine, which is a stimulant. This means caffeine can temporarily make us feel more alert or less drowsy. 

It's fine to drink tea and coffee as part of a balanced diet. But it's important that tea, coffee or other drinks containing caffeine are not your only source of fluid.