How Much Water Should You Drink Per Day?

We’re expected to keep on top of an awful lot of things these days. Food, exercise tracking, health insights. It’s exhausting. So remembering to drink enough water too can be a pain.

Remember though, you’re 60% made of the water! 

To put that into perspective, if you weigh 200 lbs, 120 of those lbs are good old H2O. 

Our bodies need it for everything from keeping blood flowing, to lubricating our joints, to digesting our food. I mean, getting enough water is hardly a fad is it? It’s an essential requirement for life! So maybe getting enough water is one thing we should all be worrying about? 

Yes and no. Dehydration causes a real drop in mood, productivity and performance. And long term it can be bad for your overall health. But drinking water isn’t all that complicated, is it? It’s something we can all fit into our lives, and it doesn’t even have to cost much.

But how much water should you be drinking per day? Check out our handy calculator to find out ideal level of hydaration.

Water Consumption Calculator 2021

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Tell us about yourself

Gender

Male
Female

Height


Weight

Age

And all this depends on a few things. 

Factors to Consider

As the DRI Report for water, potassium, sodium, chloride and sulphate confirms, how much water we each need varied based on things like height, weight, gender and overall health. You can work out a ballpark figure using the formula I will go into later, but you should also monitor how you feel and think about the following factors:

1. Where you live 

In warmer climates, we need more water because we sweat more. If you live somewhere warm, you probably need to drink more water than someone living in cooler temperatures. 

As a rule, dry climates also mean you need more water than average. This applies whatever the temperature. 

Finally, Altitude has an effect on hydration - if you’re used to it you’ll have adjusted, but if you’re going high up (over 5,000 feet) and are not used to altitude, then the Institute for Altitude Medicine recommends an extra 1-1.5 litres of water daily. (1, 2)

2. Your size 

There are various formulas for working out how much water you need based on your size. Overall, it is agreed that larger people need more water but that muscle needs more water than fat.

3. How much exercise you do 

According to a critical review on fluid and exercise/performance, you need to drink 12 extra ounces of water if you’re working out for more than 30 minutes or else performance will be affected. Other tough physical activities count too, not just the gym, so keep water with you if you have a physical job or hobby. 

4. Your diet 

According to an excellent, overarching study on our water needs in the Nutrition Review, fruits and vegetables are up to 89% water, while pizza is only 40%-49% water. Plus, fruits and veggies tend to be bulkier and heavier than processed foods so that the percentage is equal to a more meaningful chunk of your daily water needs. You see where I’m going with this? 

If you eat lower-water foods, you need to drink more of your RDA of water. Lower-hydration foods tend to be more processed foods (pretzels contain less than 10% water!) though nuts and dry legumes also have a very low water content. 

5. Your health

Some conditions may affect water retention, while some medicines are diuretic (cause you to lose water through the kidneys/urination) so you need to drink extra water while taking them. Your doctor should explain any side effects or symptoms like this to you, but if in doubt ask a healthcare professional!

6. Pregnancy and breastfeeding

A lot of the weight gained during pregnancy is actually water retention and amniotic fluid. On top of that, pregnancy is a physically difficult period for pregnant people’s bodies. For that reason, pregnant people need to drink extra water throughout the pregnancy.

Likewise, breastfeeding people need additional water to make up for what is lost through milk production and secretion. According to a Chinese study in the BMC these additional needs are often not met, so if you are pregnant or breastfeeding be extra mindful of your water intake.

How To Figure Out How Much Water You Need?

I mean, how deep do you want to go?

The Mayo Clinic advice states that men need about 15.5 cups (3.7 liters) of fluids a day and women need about 11.5 cups (2.7 liters) a day. Of course, these are averages and your body or lifestyle might mean you need more or, in some rarer cases, less.

One way to calculate optimal water intake involves taking your weight in lbs, and multiplying it by 0.67. So, if you weigh 100 lbs, you should drink 67 ounces of water. If you weigh 200 lbs, you should drink 134 ounces of water.

One top of that, add 12 ounces for every half hour of exercise you do, and the same when you are sweating due to hot weather. 

This is slightly complicated by your body composition, however. If you are very muscular, you should drink more water as muscle utilizes more water than fat does. 

Weight

Ounces of Water Daily

100 pounds

67 ounces

110 pounds

74 ounces

120 pounds

80 ounces

130 pounds

87 ounces

140 pounds

94 ounces

150 pounds

100 ounces

160 pounds

107 ounces

170 pounds

114 ounces

180 pounds

121 ounces

190 pounds

127 ounces

200 pounds

134 ounces

210 pounds

141 ounces

220 pounds

148 ounces

230 pounds

154 ounces

240 pounds

161 ounces

250 pounds

168 ounces

How Much Should You Drink When Exercising?

Again, you can keep this very simple and drink the previously mentioned 12 ounces per thirty minutes of exercise, or you can abide by the National Association of Sports Medicine's guidelines below. 

If you regularly work out a lot, you could do the necessary calculations (of fluid lost during exercise) once or twice using a good scale and use that as a guide for future water intake. Because let’s be honest, we’re not all going to weigh ourselves multiple times a day and measure out our water based on that are we? Not only would it be time consuming, it would probably also lead to an unhealthy obsession. 

I will go into how to tell if you are getting enough water later on (or you can skip down there to have a look now), but monitoring how you feel and keeping an eye on the color of your urine is usually enough to know you’re getting a healthy amount of fluid.

Workout Timing

Ounces (Oz) of Water

Before Exercise

14-22 oz of fluid 2 hours before exercise

During Exercise

6-12 oz of water or sports drink every 15-20 mins of exercise

After Exercise

16-24 oz of water or sports drink for every pound of body mass lost during exercise

Do Other Fluids Count?

Yes, they do. All fluids apart from alcoholic beverages count. In fact, for a long time it was widely believed that caffeinated beverages don’t count towards your daily water intake, but one study out of The Center for Human Nutrition, Omaha, proves that actually the diuretic effects of caffeine are negligible. In layman’s terms - tea and coffee count towards your water total!

That being said, it’s a good idea to drink largely water as other beverages might be bad for your health in other ways (carbonation, sugar, etc). According to Harvard research water gives the best health benefits of all common beverages. 

So, drink water if you can but don’t sweat it if you’re getting some of your daily liquid from other sources. Just follow the usual rules around what’s healthy and unhealthy, and avoid high-sugar beverages in excess. 

You might be surprised to find that it isn’t just liquids that contribute to you staying hydrated. Your food also contains water!

On average, people get around 19% of their daily water needs from their diets according to the Institute of Medicine of the National Academies of Sciences.

If you eat loads of fruit and veggies, you might get more. If your diet is all crackers and processed cheese you probably get less (and after you have worked out how much water you should drink every day, you might want to start thinking about making some changes to your meal plan)!

Here’s the water content range for some popular food items.

Percentage

Food Items

100%

Water

90-99%

Fat-free milk, cantaloupe, strawberries, watermelon, lettuce, cabbage, celery, spinach, pickles, squash (cooked)

80-89%

Fruit juice, yogurt, apples, grapes, oranges, carrots, broccoli (cooked), pears, pineapple

70-79%

Bananas, avocados, cottage cheese, ricotta cheese, potato (baked), corn (cooked), shrimp

60-69%

Pasta, legumes, salmon, ice cream, chicken breast

50-59%

Ground beef, hot dogs, feta cheese, tenderloin steak (cooked)

40-49%

Pizza

30-39%

Cheddar cheese, bagels, bread

20-29%

Pepperoni sausage, cake, biscuits

10-19%

Butter, margarine, raisins

1-9%

Walnuts, peanuts (dry roasted), chocolate chip cookies, crackers, cereals, pretzels, taco shells, peanut butter

0%

Oils, sugars

How Much Water Should You Drink For Weight Loss?

There is a lot of compelling evidence to suggest that increased water intake can aid with weight loss, but not a huge amount of research on exactly how much water might help you lose weight. 

For example, both older studies from the 1800s and more recent trials suggest that drinking two liters of water a day may burn an extra 23 calories. Of course, that’s pretty negligible, so is unlikely to actually do much for weight loss! (3, 4)

More promisingly, one 2013 study by Journal and Clinical Diagnostic Research had participants drink 500ml of water about an hour before each meal, and observed increased weight loss in study participants. So, the answer might be 500ml before each meal!

Generally, though, just drinking enough water (figure out how much you need, and ramp it up if you are exercising) is an important part of a balanced diet that will lead to healthy weight loss.

Drinking enough water is correlated with other positive health habits like eating a balanced diet and consuming the correct number of calories to maintain a healthy weight. A 2016 study by Journal of Human Nutrition and Dietetics based on a large experiment involving over 18,000 people concluded that increased water intake is associated with a reduction in daily calorie intake.

How to Tell if You Are Drinking Enough Water

All this information on how much water to drink can sometimes make you feel less confident you’re getting enough rather than more confident. But don’t worry, it’s easy to tell if you’re correctly hydrated, and the symptoms of dehydration are also hard to miss once you know what to look for.

It’s not exactly glamorous, but the best way to tell whether or not you are properly hydrated is by keeping an eye on the color of your urine. According to the Mayo Clinic clear or light colored urine means you are getting enough liquid. 

Rarely feeling thirsty is another signifier of being properly hydrated according to the Mayo Clinic, but it should be noted that our thirst signals weaken as we get older so elderly people may not always know when they’re becoming mildly dehydrated. 

If you are working out hard, you can also weigh yourself on a high quality set of scales before and after a workout to check how much water was lost through sweat. You can then rehydrate to the correct level by drinking the amount of water lost.

What Happens If You Don’t Drink Enough Water?

If you don’t drink enough water you will become dehydrated.

Some of the signs of dehydration are a little vague - you will be tired and potentially moody, for example. Several studies confirm that loss of energy and a dip in mood are a symptom of dehydration in men, women and children. (5, 6, 7)

Headaches are another common sign of dehydration. According to BMC Public Health about 40% of people experience a headache when dehydrated. 

You will also notice that your urine becomes dark if you haven’t been drinking enough water. This has been known for a long time, with studies on hydration levels and urination carried out as long ago as the 1800s, and as recently as 2019.

The Greek 2019 study found that there is fluctuation in urine concentration throughout the day regardless of water consumed, so don’t worry if your urine isn’t always clear as a mountain stream. (8, 9)

Other symptoms of dehydration include a sore throat and bad breath, caused by a lack of saliva. Feeling light headed could also mean you’re dehydrated.

In fact, when in doubt, have some water! Just a very small drop (1-3%) in hydration can cause symptoms of dehydration, so a glass of water is likely to help a lot.

Is It Possible to Over Hydrate?

Of course, some people who are drinking a lot of water worry about over hydration, especially if sticking to the 'when in doubt, have a glass of water'. So, is it possible to over hydrate?

Technically, yes, you can overhydrate.

The practical answer, though, is that most people aren’t at risk of drinking dangerous amounts of water. As the MSD Manual states, overhydration is more likely in older people whose kidney function has dropped, or in people with pre-existing kidney issues. It can also be a problem for professional or semi-pro athletes, particularly those taking part in long distance events like cycling tours or ultra runs. 

When overhydration happens it can lead to hyponatremia which, as the MayoClinic.org tells us, is an abnormally low concentration of sodium in the blood. This is because the sheer volume of water in your body dilutes the sodium to dangerous levels. Symptoms of this rare issue include confusion, headaches, fatigue and nausea and vomiting.

Remember though, you’re very unlikely to become overhydrated.

Tips For Hitting Your Daily Water Goal

The Mayo Clinic advises drinking a glass of water: 

  • With each meal and between meals
  • Before, during and after exercise
  • If you feel thirsty

Here are a few of my personal favorite tips for getting enough water:

  • Drink from a container that measures your water. A clear water bottle with measurements on it helps you keep track of exactly how much water you have consumed. You can set a goal in the morning - say three full 32oz bottles - and easily track your progress throughout the day.
  • Drink water before every meal. Not only does this automatically mean you’re getting water three times a day, but it may mean you are less hungry and therefore eat only what you need rather than over indulging.
  • Keep water by your bed. A large bottle of water by your bed is a good idea. Usually, people wake up thirsty. You might be able to drink a whole chunk of your recommended water intake before you even put your feet on the floor in the morning!
  • Jazz up your water! You can add all sorts to water to make it more exciting - from lemons and limes to mint and cucumber. Or, if you don’t mind spending a little bit of money, you can get plenty of flavor packs for water that don’t contain sugar or anything else nasty. And remember, things like fruit tea count so why not find one you love to make water drinking a joy?

The Bottom Line

The conclusion to all of this? Drink when you’re thirsty, drink when you sweat, and try to get around 3-4 liters of water per day minimum.

Beyond that, you’re really just fiddling with the details. If you have a goal, like maximizing performance or losing weight, you may want to be more careful and specific about your water intake, or perhaps you want to work out the optimum amount and then stick with that. But once you know the symptoms of dehydration, you should start noticing them when they happen so you can easily compensate.

As long as your urine is pale yellow or clear, though, you don’t need to worry about serious dehydration!

Water consumption can be as simple or as complicated as you want it to be, but there’s one basic rule: stay hydrated if you want to be your best self every day. 

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