Here's How Much Coffee Hydrates You, Compared To Water

We've all been told about a bajillion times that we need to drink more water. And we all know that you should really drink water first thing in the morning. Specifically, experts say you need about a gallon, or 12.5 cups, of water a day.  Of course, many factors affect that number, including your body type, your environment, exercise, age, and health conditions — just to name a few. But the good news is that you can branch out to beverages beyond just plain ol' tap water to hydrate. Coffee is one of them. Going against the popular myth, coffee does hydrate you, just not quite as efficiently as plain water. 

Coffee obviously contains caffeine, which is known to be a mild diuretic. That means it can increase urine production, especially in people who aren't regular coffee drinkers. However, studies comparing coffee and water intake have found that moderate coffee consumption (about 3 to 4 cups per day) can have similar effects to drinking the same amount of water (via PLoS One). 

The trick is not to go beyond that. If you're drinking large amounts of highly caffeinated coffee, that increased caffeine load will quite possibly increase your trips to the bathroom. Keep in mind, we're talking about multiple extra-caffeinated nitro cold brews or energy-style coffee drinks throughout the day. One 8-ounce cup of black coffee is more than 95% water, so for daily coffee drinkers, the diuretic impact should be minimal.

Practically speaking, coffee can hydrate you almost as much as water. Obviously, water is still the gold standard here because it nourishes you without adding caffeine, acidity, or calories. But, otherwise, you can go ahead and get thee to Starbucks, because coffee absolutely contributes to your total daily fluid intake. 

If you're wondering how this relates to your lattes and flat whites, bear this in mind: Black coffee is essentially water plus caffeine and trace compounds. But sugary syrups, heavy cream, and sweetened condensed milk turn it into something that is more like a dessert beverage. That doesn't take away the hydration, but it's good to keep all those extras in mind for health reasons.

If you're an athlete or working in hot conditions, relying solely on coffee isn't a great idea because it can elevate heart rate and blood pressure for some individuals. But for the average Joe sitting at a desk, your morning cup of joe absolutely "counts." And it's not just coffee. Black, white, and green teas are all hydrating, and for most people, these beverages hydrate nearly as well as water. Moreover, herbal teas (like chamomile, peppermint, or rooibos varieties) are caffeine-free, which basically just makes them delicately flavored water with antioxidants. 

The differences come down to caffeine content and frequency, not whether a drink counts as fluid. If tea helps you drink more fluids overall, well, it's doing its job. Water is always your best bet, but it's nice to have options.