A cup of coffee can be something very different from person to person and situation to situation.
Espresso? Weak americano? Strong? And then even: there is often more caffeine in a cup of filter coffee than in an espresso. Weird but true. So it differs quite a lot what you drink.
I know someone who drinks 15 cups a day, but they are very very weak. And another drank 20 stong ones a day. Myself I used to drink 10 easily, not anymore
Even the same volume(cup) of coffee brewed the exact same way will vary in caffeine content based on whether it's a light or a dark roast. I wish more studies like this would just list mg of caffeine for comparison instead.
Espresso? Weak americano? Strong? And then even: there is often more caffeine in a cup of filter coffee than in an espresso. Weird but true. So it differs quite a lot what you drink.
I know someone who drinks 15 cups a day, but they are very very weak. And another drank 20 stong ones a day. Myself I used to drink 10 easily, not anymore