While a cup of coffee is not as hydrating as a glass of water, it can count toward your daily liquid intake. "Because it acts as a diuretic, I would count coffee as about half as much liquid as it really is," physician Catherine Waldrop, M.D., tells mbg. "Forinstance, one cup of coffee would count as half a cup of water," she explains.

That said, drinking multiple cups of coffee or tea without also drinking water could end in dehydration. "A cup of coffee is not going to dehydrate you that much," integrative medicine doctor Bindiya Gandhi, M.D., says, "but many cups without water intake will."

Dry, chapped lips could be a sign you've gone overboard, gastroenterologist Will Bulsiewicz, M.D., MSCI, previously explained. Other signs of dehydration include dark yellow urine and not feeling an urge to pee often enough.

Summary: One cup of coffee would count as about half a glass of water.

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Do Coffee & Tea Count As Water? MDs Spill The (Surprising) Answer - mindbodygreen.com