How Much Water You Should Drink Every Day

Water may not be the most exciting beverage in a world of iced mocha cappuccinos and matcha teas, but you literally can’t live without it. So, how much water should you drink a day? Let’s dive into some numbers.

The Academy of Nutrition and Dietetics recommends sipping down the following for daily fluid intake:

• 100 ounces/12.5 cups (3.1 liters) for men.
• 73 ounces/9 cups (2.1 liters) for women.

But consider those numbers a starting point. Your size, metabolism, location, diet, physical activity and health all factor into how much water you need to drink per day, says family medicine specialist Saadia Hussain, MD.

That’s a lot of information to gulp down all at once, right? Well, here’s a drip-by-drip accounting.

How much water do you really need?

To determine how much water you need, Dr. Hussain suggests considering these four factors:

• Activity level. If you work out a lot or are moving all day long, drink more water to compensate for what you lose through sweating.
• Location. If you find yourself in a warmer climate or at higher altitudes, you’ll want to increase your fluid intake due to your body’s increased water loss through increased sweating and respiration.
• Metabolism. If you have a speedy metabolism and your body seems to need more fuel to keep its engines revved, it’s a good idea to down an extra glass (or two) of water during the day.
• Size. The more you weigh, the more water your body tends to need.

But water demands are also like the stock market, with daily fluctuations that depend on:

• Health. Fighting off an illness can lead to dehydration, especially if you have a fever or are losing fluids due to vomiting or diarrhea. Try increasing your daily quota of water by a few cups to compensate and help your body recover.
• Physical activity. Did you go for a sweat-inducing run or spend a few hours working in the yard? The more active you are, the more water you’ll need.
• Weather. If it’s a scorcher of a day, it won’t hurt to drink a little more than the daily recommendation as your body works to handle the heat.
• Alcohol consumption. Alcohol is a diuretic that can make you dehydrated. Before you decide on a second cocktail, drink a glass of water to rehydrate yourself and replace fluids caused by alcohol-mediated losses.

Benefits of water

Water is sometimes considered a fourth macronutrient, joining the list with protein, fats and carbohydrates. It’s required for your body to function optimally. (Fast fact: Your body is 60% water.)

“That’s why it’s so important to drink enough water every day,” states Dr. Hussain.

Drinking water can help:

• Improve blood flow. Water ensures that your blood is just the right consistency to carry oxygen- and nutrient-rich blood to the areas that need it, including your brain, heart, kidneys and muscles.
• Aid digestion. Your body needs water to break down and process the food you eat. Fluid in your system also helps soften stool and prevent constipation.
• Maintain your joints. Think of your joints like the gears of your car. They need to be well-lubricated to work and last.
• Guard against kidney damage. Drinking adequate amounts of water can help prevent kidney stones and urinary tract infections (UTIs). Staying hydrated also helps your kidneys get rid of toxins and waste from your body.
• Boost skin appearance. Drinking H2O can be just as effective as expensive anti-aging creams and lotions when it comes to keeping it clear and wrinkle-free. It can also stave off certain skin disorders.
• Protect your teeth. Water keeps your mouth clean and lowers your risk for tooth decay.

There’s also research that shows consuming enough water may enhance exercise performance, assist with weight loss, and reduce allergy and asthma symptoms.

How to tell if you’re hydrated enough

Don’t assume you’re drinking enough water even if you're not thirsty. Instead, take a peek at your urine, advises Dr. Hussain. If it’s a pale yellow color, you’re right on track. If your urine is darker or has a strong odor, then you could probably use more fluids.

Other symptoms of mild to moderate dehydration might include:

• Constipation.
• Dizziness.
• Dry mouth.
• Fatigue.
• Muscle cramps.

More severe dehydration constitutes a medical emergency that requires immediate attention. Severe dehydration can include the symptoms mentioned, as well as:

• Abdominal pain.
• Confusion.
• Lethargy.

Can you drink too much water?

Drinking too much water is hard to do, but it’s possible. Hyponatremia, or low sodium, can be caused by several things — but one of them is when people drink too much water over a relatively short period of time.

“This condition can be quite serious but it is extremely rare,” says Dr. Hussain. “It’s pretty unusual that anyone would drink so much water that they would actually hurt themselves.”

Make drinking water a habit

So, what’s the best way to make sure you’re drinking enough water without getting out measuring cups? Try to focus on sipping water regularly throughout the day, Dr. Hussain suggests.

That’s some of the rationale behind the familiar recommendation to drink eight 8-ounce glasses of water per day. (In reality, that number is somewhat arbitrary and not rooted in scientific evidence.)

Beverages such as milk, tea, coffee, juices and sports drinks count toward your daily fluid intake goal, too. But don’t overdo it on sweetened drinks with added sugar, and try to limit caffeine (a diuretic that encourages your body to shed fluid.)

“Staying hydrated is one of the most important things you can do for your overall health,” says Dr. Hussain. “It’s an easy way to help your body run like it should.”