How Much Water Should You Drink Per Day?

You may have heard that you ought to be drinking 8 glasses of water a day to stay properly hydrated. While that is a good estimate for most people, it can be a bit more complicated than that. Factors like your age, diet, and activity level can all impact your recommended amount of drinking water. Read on to find out more about the amount you should drink, and we’ve even included some tips on keeping your pets hydrated too!

How many glasses of water should you drink a day?

While everyone’s daily water intake needs will differ slightly, in general it is suggested that women should take in 2 litres of water per day, and men should take in 2.5 litres per day. However, this number accounts for water from all sources – which means the water content of your food is also included in this number!

If you were to only consume water via drinking water (which we do not recommend!), men would need to drink roughly 10 glasses of water per day and women would need to drink roughly 8 glasses. Everyone is different, but here is a general guide to how much water to drink every day to ensure you stay hydrated and meet the recommended daily water intake total.

  Glasses (250ml) Millilitres (ml) Litres (l) Pints Fluid Ounces (fl oz)
Adult Man * 10 2,500 2.5 4.4 88
Adult Woman * 8 2,000 2.0 3.5 70

* Recommended intake calculated based on scientific opinion from the European Food Safety Authority (EFSA) 

Of course, given that we take in water via our food too (roughly 30%), a couple of glasses less than this is absolutely fine. The most important thing is to listen to your body and to drink some water whenever you feel thirsty, as this is the best indicator that you are becoming dehydrated. But if you can, you should keep drinking water throughout the day before signs of thirst set in, as this will mean your hydration is always at a good level. 

If you are suffering from any medical conditions or infection, always heed the advice of your doctor on how much water you should be drinking. 

How much water should a child drink?

The amount of water that children should take in per day changes as they grow up. Before the age of 8, the recommended intake for boys and girls is the same regardless of sex. In the pre-teen years (aged 9-13), the recommendations do split, and it is recommended that boys take in slightly more water per day. From the age of 14 upwards, children should follow the total daily intake amounts provided for adult men and women (see above). 

  Glasses (250ml) Millilitres (ml) Litres (l) Pints Fluid Ounces (fl oz)
Boy (aged 9-13) * 8.5 2,100 2.1 3.7 74
Girl (aged 9-13) * 7.5 1,900 1.9 3.3 67
Child (aged 4-8) * 6.5 1,600 .6 2.8 56

* Recommended intake calculated based on scientific opinion from the European Food Safety Authority (EFSA) 

Water and exercise

When we exercise, the body loses water via sweat and your increased breath rate. To be able to exercise at an optimal level, you need to make sure you are drinking enough water before, during and after exercise. This will to an extent depend on the type of exercise you are doing, how long for, and the conditions you are exercising in (temperature, humidity, and so on). 

Generally, you should aim to drink a large glass of water roughly half an hour prior to starting your exercise, another glass of water every 10-20 minutes throughout the period you are exercising, and another glass within the half hour period after you finish exercising. This will help to regulate your body temperature, lubricate your joints, and avoid symptoms of dehydration like a headache, muscle cramps, or feeling light-headed or dizzy.

How much water should pets drink a day?

It’s not just our own water intake that we need to keep an eye on – our furry friends also need to stay well hydrated. As with humans, your pet’s water intake can also come from their food, so if your pet eats a lot of wet food, don’t be surprised if they tend to drink slightly less than this.  

How much water should a dog drink a day?

In general, most dogs need to consume about 1 fluid ounce of water for every pound of bodyweight they have. For example:

  • – A small dog (around 14lb, or 6kg), e.g. a pug, would need to consume 14 fl oz of water per day – just under half a litre
  • – A medium dog (around 70lb, or 31kg), e.g. a collie, would need to consume 70 fl oz of water per day – around 2 litres
  • – A larger dog (around 100lb, or 45kg), e.g. a rottweiler, would need to consume 100 fl oz of water per day – around 3 litres.

But just like humans, every dog is different. Not just when it comes to size, but also in terms of diet, exercise, and any pre-existing health conditions. Not to mention how dogs of different fitness and fur thickness cope during warmer weather. 

You should make sure your dog has an easily accessible water bowl and keep this topped up throughout the day, as well as taking some water provisions with you on any long walks. Be sure to keep an eye on how much water your dog is drinking each day and notify your vet of any significant changes. 

How much water should a cat drink a day?

The average cat should consume about 3.5 to 4.5 fluid ounces of water for every 5 pounds of bodyweight they have. So a common house cat that weighs around 9lb, or 4kg, would need to consume 6.3 to 8.1 fl oz per day – around 180-240ml. 

Don’t be surprised if you don’t see your cat drinking water throughout the day – they can be quite private animals. As long as the level of their water bowl is going down, you know they’re getting the fluid they need. And always be sure to report any significant changes in their water consumption to the vet. 

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