Here's what the maximum amount of caffeine you should be drinking in a day looks like

And you thought Red Bull was bad.

Turns out that while a can of the vilified energy drink has 80 mg of caffeine (less than a quarter of the amount you should have each day, according to the Mayo Clinic), one small cup of Starbucks drip coffee has nearly 5 times that amount.

Regardless of how you get your caffeine, it's important to keep in mind that it's a stimulant with some positive and negative effects.

And the amount of caffeine that's in various drinks - or even the same drink from a different chain - can vary drastically. Here's how much caffeine is in everything from a can of Coke to a plain coffee from McDonald's: