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When It Comes to Water, One Size Does Not Fit All

How do I know how many glasses of water I need to drink each day?

8 glasses of water – or 64 ounces – has become the de facto guideline for water intake. That said, the U.S. National Academies of Sciences, Engineering, and Medicine recommends a much higher daily fluid intake of 3.7 liters (125 ounces or 15.5 cups) for men and 2.7 liters (91 ounces or 11.5 cups) for women.

Why the discrepancies? First of all, there is fluid in the foods that we eat (particularly fruits and vegetables), as well as other beverages such as coffee or sodas that people might consume. But that’s just one piece of the puzzle. The truth is that the actual amount of water your body needs will depend on several factors unique to yourself and your environment. There is no one-size-fits all number when it comes to hydration, so let’s dig into all the factors that you need to consider when you come up with your own baseline.

And then there’s the three biggest factors to consider: 1) pregnancy, 2) exercise and exertion, and 3) weather conditions.

For the vast majority of people, though, being under-hydrated is not an acute problem that poses immediate health risks. Your body will adjust to a less-than-ideal amount of water intake — but at a cost, which can potentially be dangerous over the long term. All of the organ systems in your body can end up suffering if they regularly lack sufficient hydration, year after year. On the other hand, consistent and proper water intake — based on your own particular needs and circumstances — has incremental, enduring benefits for health and well-being, as well as improvements to mood and outlook.

Ok, so if 64 ounces (or 3.7 liters, for that matter) is just a guide, and one-size-does-not-fit-all — given all the factors outlined — above, where do we begin? Here’s the simple calculation: divide your body weight by two-thirds. That number is the baseline amount of water you should consume daily in ounces. So, for example, if you weigh 150 pounds, you’ll want to start with 100 ounces — or just under 3 liters of water. 

If you want to get more precise based on the  factors above – your diet, your location, pre-existing medical conditions, exercise, and weather – fill in the following questions:

TOTAL: ________ 

That’s a more precise daily target for your target daily water intake in ounces than the simple ⅔ of your body weight (but the numbers will likely be pretty close).. 

Then, space out your water consumption over the course of the day, starting with a glass of water in the morning before breakfast, then having a glass of water with each meal. Sip a few glasses between meals, and another glass before bed. Avoid gulping down huge amounts of water in one sitting. Some people like measuring out their water each day, and that can be a handy way to start the process so that you can get a sense of what it takes to hit your daily goal. Just keep in mind that if hydration becomes a chore or something you have to think too much about, it will be difficult to integrate permanently into your daily habits.

Another tip that we at Hint like to remind people: mix it up and make it delicious. A little flavor goes a long way, especially when it’s really true to its fruit origin. We’ve spent years perfecting our water flavors and ensuring that they have no sugar, sweeteners, or preservatives. Try them out yourself; we have a variety pack waiting for you with twenty-four fruit flavors at

One last note: what about overhydration? It’s rare, but it’s a real thing — especially now with extreme sports such as triathlons becoming more popular, not to mention countless online “challenges” that summon people to fill up a gallon jugs and guzzle down huge amounts of water in a couple sittings each day. Figure out your particular hydration needs, work toward that number, and take it slow, spreading out your consumption over the course of your day.

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