As a true coffee lover, it’s not uncommon for an entire day to pass for me to realize I’ve consumed 3 to 4 cups of coffee and hardly any water at all. There’s something about coffee that just goes down so easy. At the same time, I don’t find myself thirsty for water after drinking multiple cups of coffee. After all, brewed coffee is about 98 to 99% water, right? This argument probably sounds good — at least if you’re a fellow coffee addict. But does coffee count as water intake? If you ask me, it should; but here’s what the medical professionals say how you should track your water and coffee intake.
Does coffee count as water intake?

Coffee lovers will be happy to hear that most experts do believe that coffee can count towards your daily fluid intake. According to Dr. Joseph Mercola, Board-Certified Family Physician and author of ‘Your Guide to Cellular Health’, “Studies show that habitual coffee drinkers get similar hydration benefits from coffee as they do from water. However, it’s smart to balance coffee with other fluids such as milk or coconut water. Those beverages stay in your system longer because they empty from your stomach at a slower rate.”
Other experts in the field, such as Tricia Best, a Registered Dietitian at Balance One Supplements, agree that while water can count towards your daily fluid intake, it’s still important to pay attention to how much coffee vs. water you’re actually consuming. “Those taking certain medications or who are very sensitive to caffeine should limit their coffee intake,” says Best.
Does coffee dehydrate you?

In asking “Does coffee count as water intake?” many also wonder if the myth around coffee causing dehydration is true. If it’s true that coffee causes dehydration, you’d think it shouldn’t count as your daily water intake. Dr. Mercola says the research doesn’t support this claim and that it does contribute to hydration the same way that water does.
“Even with its caffeine content, coffee doesn’t cause dehydration in regular drinkers. The mild diuretic effect of caffeine may make you urinate more often, but you don’t lose more fluid than you take in. A study published found that men who drank three to six cups of coffee per day maintained the same hydration status as when they drank water, based on total body water and blood and urine tests,” says Dr. Mercola.
For the average person, moderate coffee intake of about three to six cups per day is not enough to cause dehydration. “Problems usually appear only if you consume caffeine far beyond that range or if you’re already dehydrated. Your tolerance also depends on whether you drink coffee regularly. Habitual drinkers adapt to caffeine’s effects, which means your kidneys don’t flush out extra water the way they might if you rarely drink coffee.”
“Black coffee and espresso provide the same hydration benefit as water. Once you add milk, you may actually boost hydration slightly because of the added fat and protein. A latte or cappuccino hydrates a little better for that reason. Sugar, on the other hand, can work against you. High-sugar drinks can pull water into your intestines and may leave you feeling thirstier later, especially if you drink several sweetened coffees a day.”
Should you count coffee as part of your daily water goal?

While you can count water towards your daily hydration goal, that doesn’t mean you should ditch water for coffee entirely. Dr. Mercola says water still wins for pure hydration efficiency because it’s absorbed quickly and doesn’t add calories, sugar, or other compounds. According to Best, coffee drinkers can follow one simple rule to make sure they’re balancing coffee vs. water intake properly. “Coffee, tea, and low-sugar beverages can count towards your hydration for the day, but aim for at least half of those to come from water,” she recommends. Drinking too much coffee (in place of water) can lead to other problems, too, such as a fast heart rate, stained teeth, and anxiety.
According to the Mayo Clinic, daily hydration goals vary based on your body weight and size. In general, it’s recommended that men consume 15.5 cups of fluids per day and women consume about 11.5 cups of fluids per day. Fluids do not just refer to water and can also include coffee, too.
What is the two-hour coffee rule?
I first heard about the “two-hour coffee rule” on TikTok, where I learned it’s best to drink water before rushing downstairs to make your morning coffee. “The two-hour coffee rule refers to waiting about 90 to 120 minutes after you wake up before drinking your first cup of coffee,” says Dr. Mercola. The reasoning behind this “rule” focuses on adenosine—a molecule that builds in your brain during the day and makes you feel sleepy. When you first wake up, adenosine levels are naturally low, and your body already boosts alertness through a surge of cortisol.”