Coffee—or more specifically, caffeine—is a stimulant and is thus considered to be a drug; it is even called the “world’s most popular psychoactive drug.” And with all substances, caffeine consumption comes with a risk of overdose, but what is that level in terms of coffee? A claim floating around the internet is that 42 cups of coffee in a day would be a lethal dosage, but as Yahoo! Sports reports, it’s a bit more complicated than that (and not nearly as scary sounding).
The 42-cup claim stems from a post by Twitter account @Fact based on a 2011 New York Times article. That number, which implies that the ultimate question of life, the universe, and everything is “how many cups of coffee can you drink in a day before you die,” is derived from a simple algebraic equation involving the minimum lethal dose of caffeine and the amount of caffeine in a standard cup of coffee, give or take. Yahoo! Sports states that 5,000mg caffeine is given as the minimum dose with an 8oz cup of coffee having anywhere between 80 and 100mg. So if you drink 42 cups of coffee, the reasoning goes, you have consumed enough for a potentially lethal dose.
But as the article notes, it’s not quite that simple. For one, the FDA estimates the lethal caffeine dosage to be much higher, anywhere between 10,000 and 14,000mg. But even assuming that 42 number to be generally accurate, from a practical perspective, it is unlikely you could even drink that much coffee fast enough for the caffeine to be lethal. For the caffeine to be a lethal dose, it needs to be consumed all at once, and drinking over 2.5 gallons of coffee would be extremely difficult, if not impossible, to do.
Still, there are some individuals who may be more sensitive to caffeine, particularly those with underlying heart conditions, who could experience a toxic dose of caffeine at a much lower level, around 1,200 mg, that may lead to seizures, tachycardia, or arrhythmia. If one of these individuals downed just 2.5 cups of high-caffeinated coffee, like the 500mg per serving Death Wish, they would be consuming potentially dangerous amounts.
Nonetheless, save for the worst possible scenario where caffeine-sensitive people are shotgunning extra-caffeinated coffee, the risk of overdose from coffee is practically non-existent. So go ahead, drink your five cups of coffee a day. Chances are, it’s doing you more benefit than harm.