How Much Water Should You Drink a Day?

By Joe Boland

August 16, 2024

Staying hydrated is essential for overall health, but how much water should you drink a day?

The answer isn’t one-size-fits-all. It varies depending on factors such as age, activity level and overall health.

While there is no universal guideline for daily water intake, understanding individual needs can help ensure adequate hydration.

This article will guide you through understanding your daily water needs, the importance of staying hydrated and the potential risks of drinking too much water.

How Much Water Do You Need? Recommended Daily Intake

The recommended daily water intake can vary based on age, gender and activity level. While the common recommendation is to drink eight 8-ounce glasses of water per day (known as the “8×8 rule”), this may not be adequate for everyone.

On average, healthy adult men require about 125 ounces (15.5 cups or 3.7 liters) per day, while women need around 91 ounces (11.5 cups or 2.7 liters). These recommendations can change based on factors such as age, weight and lifestyle.

For children, water needs are generally lower, and the best drinks are water and milk.

Here’s more on the average drinking water needs by age:

• Infants (0–6 months):  Typically get their hydration from breast milk or formula.
• Children (1–3 years): About 4 cups (32 ounces) of water per day.
• Children (4–8 years): About 5 cups (40 ounces) per day.
• Children (9–13 years): 7–8 cups (56-64 ounces) per day.
• Teenagers (14–18 years): 8–11 cups (64-88 ounces) per day.
• Adults (19+ years): For women, around 9 cups (72 ounces) per day; for men, about 12.5 cups (100 ounces) per day.

Another recommendation is to drink 25% to 50% of your body weight in ounces of water per day. For instance, if you weigh 170 pounds, you should aim to drink 85 ounces of water per day ideally, or at least 42.5 ounces.

Other health authorities provide the following recommendations:

• The Institute of Medicine recommends between nine and 13 cups per day for adults.
• Harvard Medical School tells us that four to six cups is a standard recommendation for generally healthy people.
• Studies conducted by the National Institutes of Health suggest between six and 12 cups per day is adequate.

There are other factors that many up how much water you should drink a day, such as:

• Location. If you live in the mountains, at a high elevation, or in hot, humid or dry areas, you likely need to up your water intake.
• Diet. If you drink a lot of caffeinated beverages or less hydrating drinks, you may need more water because you urinate more frequently, losing more water in the process. Salty, spicy and sugary foods can increase water needs as well, and you’ll need to drink more if you don’t consume many hydrating foods.
• Season and temperature. When it’s hotter outside, you typically sweat more and thus need to drink more water.
• Activity level. Those who exercise and are more physically active require more water than those who only move moderately or those who live sedentary lifestyles.
• Health. Certain medical conditions can cause greater water loss or dehydration. For instance, diabetics typically need to drink more, and dealing with diarrhea can cause rapid fluid loss.
• Pregnancy or breastfeeding. Women who are pregnant or breastfeeding need to drink more water to stay hydrated, since they’re basically drinking for two (or more).

These recommendations include all fluids consumed, not just water. Remember that individual needs may vary based on physical activity, climate and health conditions.

Importance and Effects of Drinking Water

Water is vital for nearly every function in your body. It helps regulate body temperature, transport nutrients, keep joints lubricated, aid digestion, protect sensitive tissues and remove waste.

Staying well-hydrated can also improve cognitive function, boost physical performance, increase energy, improve skin health and support overall well-being.

Here’s more on the benefits of drinking water:

• Cognitive Function: Proper hydration is linked to improved concentration, alertness and memory.
• Physical Performance: Dehydration can lead to fatigue, reduced endurance and muscle cramps.
• Digestive Health: Water aids in digestion by helping break down food and absorb nutrients.
• Kidney Function: Adequate water intake supports kidney function by flushing out toxins.
• Skin Health: Drinking enough water can help maintain skin elasticity and hydration.

Does It Aid Weight Loss?

Drinking water can support weight loss in several ways, although it is not a standalone solution for losing weight. Here’s how water can contribute to weight management:

1. Appetite Suppression: Drinking water before meals can help you feel fuller, which may reduce overall calorie intake. This is because water can take up space in the stomach, sending signals to the brain that you are full, thus reducing hunger.
2. Calorie-Free Hydration: Replacing high-calorie beverages, such as sodas and juices, with water can significantly reduce calorie intake. Water is calorie-free, making it an excellent choice for those looking to cut down on liquid calories.
3. Metabolism Boost: Some studies suggest that drinking water, especially cold water, can temporarily boost metabolism. This increase in energy expenditure can help burn more calories at rest.
4. Fat Burning: Water is necessary for lipolysis, the process of breaking down fat. Adequate hydration is essential for metabolizing stored fat and carbohydrates.
5. Improved Exercise Performance: Staying hydrated is crucial for optimal physical performance. Water helps maintain muscle function and reduces the risk of cramps and fatigue, enabling more effective workouts.

While water can aid in weight loss by helping to reduce calorie intake and enhance metabolism, it should be part of a broader weight loss strategy that includes a balanced diet and regular exercise. Drinking water alone is not sufficient for significant weight loss.

Water Sources

Water doesn’t just come from your tap. It’s also found in foods and other beverages.

Here are some common sources of water:

• Tap Water: Most commonly consumed and accessible (though beware of tap water toxicity).
• Bottled Water: Convenient but can be more expensive and environmentally impactful.
• Hydrating Foods: Fruits and vegetables like cucumbers, watermelon and oranges have high water content.
• Other Beverages: Milk, black coffee, herbal teas and real juices also contribute to your daily water intake. Be mindful of sugary or caffeinated drinks, as they may have dehydrating effects.

How Much You Need During Exercise

When you exercise, your body loses water through sweat, so it’s crucial to increase your fluid intake before, during and after physical activity. Many experts recommend adding 12 ounces of water for every 30 minutes of exercise.

Here’s more on how much water to drink for exercise:

• Before Exercise: Drink 16–20 ounces of water about 2–3 hours before exercising. Consume 8–16 ounces of water 15–30 minutes before starting your workout.
• During Exercise: Consume 4–10 ounces every 10–20 minutes during exercise, aiming for 8 or even 10 ounces every 15 minutes during high-intensity exercise. For workouts longer than an hour, consider healthy electrolyte drinks to replenish electrolytes.
• After Exercise: Drink 16–24 ounces of water for every pound of body weight lost during exercise. Electrolytes are lost through sweat, so consider drinking beverages that replenish both fluids and electrolytes, especially during intense or prolonged exercise. Include a snack with electrolytes and carbohydrates to aid recovery.

Thirst and Indicators of Hydration

Thirst is your body’s natural indicator that you need water, but it’s not always the best measure of hydration. By the time you feel thirsty, you may already be slightly dehydrated.

Other indicators of hydration include:

Can You Drink Too Much Water?

While staying hydrated is important, drinking too much water can lead to a condition called hyponatremia, where the sodium levels in your blood become dangerously low. Symptoms of hyponatremia include nausea, headaches, confusion, and in severe cases, seizures or coma.

This is more common in endurance athletes who consume excessive amounts of water. It’s important to balance water intake with electrolyte levels, especially during prolonged exercise.

Other signs of water intoxication include:

• Headaches, confusion and disorientation.
• Nausea and vomiting.
• Impaired mental state and psychotic symptoms, such as experiencing psychosis, delirium, inappropriate behavior, delusions and hallucinations. Sometimes these symptoms can also contribute to water intoxication because the person doesn’t realize what is happening and doesn’t seek help.
• Muscle weakness, cramping, twitching, aches and fatigue.
• Difficulty breathing.
• Frequent urination.
• Changes in blood pressure and irregular heartbeats.
• Severe drowsiness, seizures, respiratory arrest, brain stem herniation, and coma.

This is why you want to avoid excessive water intake. Stick to the recommended guidelines, and listen to your body.

It’s also important to monitor hydration during exercise. Be especially cautious during endurance activities where you may be tempted to over-hydrate.

Water FAQs

Q: Does coffee count toward my daily water intake?

A: Yes, coffee does contribute to your daily fluid intake, although it’s best to consume it in moderation due to its diuretic effect.

Q: Should I drink water even if I’m not thirsty?

A: Yes, especially in hot weather or during exercise. Don’t rely solely on thirst as an indicator.

Q: Is sparkling water as hydrating as still water?

A: Yes, sparkling water hydrates just as well as still water, but watch for added sugars or sodium in flavored varieties.

Q: How can I increase my water intake?

A: Carry a water bottle, eat water-rich foods, set reminders or flavor your water with fruit slices.

Q: How does climate affect water needs?

A: People in hot, humid or dry climates may need more water to compensate for increased fluid loss.

Q: Does age affect hydration needs?

A: Yes, older adults may not sense thirst as strongly and should be mindful of their water intake.

Conclusion

• Understanding how much water you should drink each day is key to maintaining your health and well-being.
• By following recommended guidelines, paying attention to your body’s hydration signals and adjusting your intake based on activity level and environmental conditions, you can ensure you’re getting the right amount of water for your needs.
• Remember, while staying hydrated is vital, it’s equally important to avoid excessive water consumption. Stay informed, and stay hydrated!