Whether you're a coffee or tea aficionado—or you simply just can’t start your day without a mug of something caffeinated—chances are you've Googled this question yourself. 
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The spiking culture of energy drinks, super-sized coffees, and blended coffee drinks is leading to growing caffeine consumption, but have you asked yourself how much caffeine is too much? You should because (spoiler alert!) it is possible to overdo it on caffeine. The consequences can be scary, even fatal. But armed with the right information about how much is too much, you can happily sip that cortado—or (gasp!) three.

Experts say it’s perfectly safe to drink up to 400 milligrams of caffeine a day (aka there aren’t any long-term health risks in healthy folks). That translates to about 3 to 5 cups of coffee a day, 8 to 9 cups of black tea or about 14 cups of green tea.

But the amount of caffeine can vary across brand, variety and roast so you might want to do a little digging into your favorite sip. For example, a 20-ounce (Venti-sized) Starbucks Blonde roast delivers about 425 milligrams of caffeine while their double espresso clocks in at just 150 milligrams. Drink a 17-ounce Honest Tea Organic Lemon Tea and you’ll get 90 milligrams, or have a similarly sized Gold Peak Unsweetened Tea and you’ll only drink 23 milligrams of caffeine.

The good news is that it’s not just “safe”: there are some legitimate health benefits to consuming caffeine. Research shows it may protect you against Parkinson’s disease. Plus, regular coffee drinkers have a lower risk of developing both Type 2 Diabetes and heart disease. (Not so, though, if your cup of joe comes with copious amounts of cream or sugar.)

Go above and beyond consuming 400 milligrams of caffeine a day and that’s where the research gets thin—as in there are still unanswered questions. But experts do know that it’s possible to consume toxic levels of caffeine. And some beverages like energy drinks make it easier to overdo it in part, because of their sweet flavor, they’re easy to chug. Another cause for concern is that energy drink makers don’t have to list how much caffeine is in their drink unless it’s being added as pure caffeine, meaning the label may not fully reflect the total amount of caffeine you’re downing. In other words, it could be significantly underestimating the grand total.

There also isn’t much research on kids and adolescents drinking caffeine and, in fact, the American Academy of Pediatrics advises against it altogether.

Bottom line? Like all things, think moderately. And listen to your body because we all respond to caffeine differently: drink too much and you’ll feel jittery or restless, your heart rate may pick up, or perhaps have an upset stomach, or insomnia.