How Much Water Should You Drink a Day? What the Science Says in 2025
Exactly how much water should you drink a day? That’s a question everyone should know the answer to. Water is one of the most important things you can consume for a healthy body. Since humans are made up of about 60% water, many of the body’s most essential functions require water to work correctly.Â
According to Medical News Today, water is good for lubricating joints and cartilage, delivering oxygen, flushing waste and improving skin health, among other functions. Nearly every system and part of the body relies on water in some way.
Scientists have often studied how much water should you drink a day to find the recommended amount. While there have been many recommendations, the results don’t seem to point to just one singular answer. In fact, the amount of water you should drink is highly individualized. Factors such as your health, your activity level, your age and weight can all affect your recommended daily amount of water.
While there may not be a set amount for every person, it’s well known that not drinking enough water can be detrimental to your body and your health. Dehydration can have serious effects. In this guide, we’ll explain how to find out how much water should you drink a day for a happy, healthy and hydrated body.
Jump to Section
- How Much Water Should You Drink a Day?
- How Much Water Should a Woman Drink a Day?
- How Much Water Should You Drink a Day to Lose Weight?
- How Much Water Should You Drink Based on Your Weight?
- How To Include More Water in Your Day
- Symptoms of Drinking Too Little Water
- Symptoms of Drinking Too Much Water
- How Much Water Should You Drink a Day FAQs
How Much Water Should You Drink a Day?
How Much Water Should an Adult Drink a Day?
As stated, there are a couple of different factors that affect that amount. One of those is age. So, how much water should an adult drink per day? In general, it’s recommended that adults drink between 11 and 15 cups of water a day. This can be broken down further into gender.Â
For example, men 19 years old and older should have about 13 cups, while women 19 years old and older should have about nine cups. How much water should you drink a day in liters? The answer is around 3.7 liters and 2.7 liters, respectively. Again, this is an estimated recommended amount.
For some, this might be a lot of liquid to consume. However, you don’t have to drink all of your water to get the recommended daily amount. Some foods, particularly fruits and vegetables, have high water content that can add to a daily water total. Watermelon, cantaloupe, lettuce and cucumber are a few of the water-dense foods. So, while you search for healthy lunch ideas for adults, you can seek out foods that will help you consume more water.
Another factor to consider is your activity level during the day. If you work out, have an active job or are on your feet all day, you will most likely need more water than the recommended average to replenish the water you’ve lost by sweating.
So, how much water should you drink a day? For most adults, a minimum of two liters is preferable. Consult a doctor to get a more accurate and personalized amount.
How Much Water Should Kids Drink a Day?
In general, most kids require less water per day than adults. Similarly to adults, though, the amount of water kids require varies on a few factors. The first factor is age. The younger the child is, the less water they’ll need. For example, 1-year-olds only need about 8 ounces of water while a five-year-old requires about 40 ounces. Kids 9 and older are recommended to have 64 ounces of water a day.
Another factor in answering the question "How much water should kids drink?" is their weight. Weight is a more accurate measurement for older children and teenagers. For example, kids who weigh 120 pounds are recommended to have 70 ounces of water a day compared to children who weigh 200 pounds, where 90 ounces of water is the recommended amount.
Like adults, kids don’t have to only drink their recommended amount of water. So, consider water-dense foods when choosing healthy snacks for kids. This can be an easy way to reach their recommended amount without excessive drinking.
It’s important to note that babies under 6 months shouldn’t drink water at all. And even after that, they don’t need much. Babies get the water they need from breastfeeding. Giving babies water can fill their stomachs and dilute their calorie intake. So, it’s best to stick to breastmilk or formula for the first 6 months.
In mL, a child should drink between 820 mL and 1530 mL per day. If you’re still not sure, consulting a doctor is the best course of action.
How Much Water Should a Woman Drink a Day?
How much water should a woman drink a day? The average woman should have about 11.5 cups of water a day. Of course, as stated, this number may need to be adjusted depending on lifestyle factors. Regular exercise or any activity that makes you sweat or exert yourself will require you to drink more water.
One of the biggest factors for how much water should an adult drink per day as a woman is being pregnant or breast-feeding. During both of these periods, you may be required to drink additional fluids or eat more water-dense foods to keep you hydrated.
So, how much water should you drink if you’re pregnant? Between 8 to 12 cups a day. And you may need more as your pregnancy progresses. Women who are breastfeeding may need to drink as much as 16 cups of water or other hydrating fluids per day. Adequate water intake helps breast milk production, so it’s important to stay hydrated for you and your baby’s health.
How Much Water Should You Drink a Day to Lose Weight?
If you’re looking to lose weight, drinking more water can be a major benefit. Water can help suppress your appetite to help you eat fewer calories. It can also stimulate your metabolism and can help hydrate you after exercise. Water also helps the body burn fat. So, how much water should you drink a day to lose weight?
Science has not found a specific amount of water that helps aid or increase weight loss. So, you should continue to drink the recommended amount of water depending on your gender, weight, activity level and other factors.
However, you can use water to help you shed a few pounds. So, how much water should you drink a day to help you lose weight? Drink a glass of water before dinner to help fill you up and reduce calories. A glass of water with and during dinner plus light dinner ideas can help you be in a calorie deficit.
Drinking water while working out can help you exercise more efficiently as well. This can keep you hydrated as you engage in activities that will help you lose weight or build muscle along with high protein meals.
Replacing sugary and high-calorie drinks with water can also help you lose weight. You may not be aware of how many of your calories you’re consuming through liquids and how that can add pounds. Make those eight cups of water instead of drinks like juices and sodas that can add sneaky calories.
There may not be a definitive answer to "How much water should you drink a day to lose weight?" However, drinking water can be a great tool when it comes to losing weight or keeping it off. For most people, between 8 and 12 cups is the right amount to maintain a healthy weight.
How Much Water Should You Drink Based on Your Weight?
How much water should you drink a day based on weight? Since our bodies need water to function, the makeup of our bodies can tell us how much water we should drink. One way to calculate is to divide your body weight in pounds in half. The resulting number is the number of ounces of water you should drink per day.Â
Another calculation is to drink about .5 to 1 ounce of water per pound. So, if you want a quick calculation of how much water should you drink a day, this gives you a pretty good estimate.
How To Include More Water in Your Day
Challenge Yourself and Others
How much water should you drink a day in oz? It can be difficult to remember to drink those 88 to 120 ounces every day. That’s why making a game or challenge out of drinking your water can help to achieve that goal.Â
Make a game of drinking a certain amount of water by a certain time of day. Challenge your friends, family or coworkers to see who can be the most consistent about fulfilling their water drinking goal.
Eat Water-Dense Foods
When it comes to searching for what to eat, many people turn to their favorite comfort foods. But if you want to consume more water, a sneaky way to do it is to eat it. Water-dense foods like watermelons, cantaloupe, oranges, lettuce, celery and cucumber all have a high concentration of water. These can keep you hydrated without having to add an extra cup of water.
Track Your Intake
Keeping yourself accountable is a great way to ensure you’re getting enough water. How much water should you drink a day? Choose an amount and keep track of the ounces or cups throughout the day as you drink. You can do this in an app, in a journal or simply with tallys.
Add It to Your Routine
Make drinking water a part of your daily routine. Have a glass when you wake up in the morning, after brushing your teeth, with meals or before bed. Tying it to other routine actions during the day can help you remember to drink. You can also set an alarm to remember to drink it.
Flavor Your Water
If you like the flavor of soda or juice but don’t want to completely give it up, consider naturally flavored water. Use lemons, limes, oranges, cucumbers and other fruits to give the water a bit of taste.
Use a Reusable Water Bottle
A reusable water bottle can help you stay hydrated when you’re on the go. Purchase a reusable water bottle or cup and divide 88 by how much it holds. That should tell you how many full bottles you should drink.Â
For example, if a water bottle is 16 ounces, you should drink that full bottle 5.5 times to reach the recommended 88 ounces of water. Plus, reusable bottles make great relaxation gifts for those who like to sit and read, do yoga or take walks.
Symptoms of Drinking Too Little Water
Many people wonder how much water should you drink a day, but they may not know what happens if you don’t drink enough water. Drinking too little water can lead to dehydration. And even minor symptoms can be bad for bodily functions. Being thirsty is a sign of minor dehydration. But a lack of water can cause some more serious issues.
How much water should you drink a day as an adult? Between 11 and 15 cups. Drinking less than this can lead to a headache, dizziness, lightheadedness and fatigue. You may also experience delirium or confusion. A dry mouth or dry cough is also common. It can affect your heart by raising your heart rate and lowering your blood pressure. You can lose your appetite, your feet can swell and you may be more prone to muscle cramps.
When kids drink too little water, they may have dry tongues or lips or no tears when they cry. In infants, less than six wet diapers per day is a sign of dehydration. And for toddlers, no wet diapers for eight hours means they’re not getting enough water. Sunken eyes, dry, wrinkled skin, deep and rapid breathy and blotchy hands and feet are all signs they’re not drinking enough water.
Symptoms of Drinking Too Much Water
When searching for the answer to the question of how much water should you drink a day, you may think the more water the better. However, drinking too much water is a possibility, and being overhydrated can be just as dangerous as being dehydrated.
One of the easiest symptoms of drinking too much water to identify is nausea and vomiting. If this is the case, you’ll want to reduce your fluid intake immediately and not drink any more water.
Other signs of overhydration are cloudy thinking, weakness, spasms, cramps and headaches. With these, you can stop drinking fluids and usually recover in a few hours. More severe symptoms can be mental confusion, seizures, falling unconscious, or a coma. With more severe symptoms, you’ll want to seek medical attention immediately for treatment.
Excess water can dilute kids’ sodium levels. Many early symptoms are similar to adults like nausea, bloating and vomiting. Kids can also experience drowsiness, confusion, irritability, headaches and muscle cramps.
How Much Water Should You Drink a Day FAQs
Is 1 Gallon of Water a Day Too Much?
For some people, a gallon of water is okay, but for most, it might be too much. A gallon of water is at the upper limits of daily water requirements. Men should have about 3.7 liters, while women should have about 2.7 liters. 3.7 liters is just under a full gallon. You may need more water if you’re exercising, exerting yourself or sweating a lot.
However, drinking too much water at one time is what usually causes overhydration. Consuming a gallon in one sitting can cause the detrimental symptoms of drinking too much water.Â
Is 2 Litres of Water a Day Enough?
So how much water should you drink a day in liters? 2 liters is 8 cups of water, which is sufficient for most individuals. You may need more if you’re active or in a hotter or more humid climate. However, 2 liters of water throughout the day is a sufficient amount for many.
Scientists have been researching how much water should you drink in a day for many years. Drinking water is one of the simplest and most important things you can do to keep your body and its functions healthy. Drinking water and eating food that contains water helps replenish what you’ve lost. However, the question how much water should you drink a day has a different answer depending on your gender, activity level, health and other factors. Determine how much you need and try to get the recommended amount every day to maintain a healthy body and keep your body functioning at a high level.Â
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