With a quality espresso machine at your fingertips, you might have some concern that you may suffer from caffeine overdose. But how much is too much? While some studies have shown that a high caffeine intake can result in hallucinations, that state might not be one of concern for some of you out there...so here's a more 'scientific' method: The Death by Caffeine calculator over at energy fiend! Simply enter your weight and select your caffeinated poison of choice to find out what your lethal limit is. How many shots of espresso before we hear the angels' gilded horns Don't worry, we're on it.