# What is the lethal dose ( LD50 ) of coffee?

Of course, there are many types of coffee, so I would like a range of lethal dose amounts for the average human, from the mildest of lattes to the most hardcore of espressos.

Pure caffeine's lethal dose is easily calculable, but what about coffee?

According to one reference:

LD$_{50}$ for coffee = 118 servings at 240 ml each; and

LD$_{50}$ for espresso = 175 shots (volume not specified),

for a 75 kg person.

A much more comprehensive quantitative description is given here for the LD$_{50}$ of coffee for an 80 kg person (113 cups at 250 mL each, 135 mg caffeine per serving). They account for half-life of elimination of caffeine, and arrive a the conclusion that one can't actually reach the LD$_{50}$ (15,360 mg) for caffeine due to metabolism, elimination, and the limit on how much water can be processed by the kidneys.

Finally, as noted in the last reference and hinted at above, the amount of water a person would imbibe on the way to reaching the 113 cup total (about 30 L) would likely kill the person (water intoxication).

• That said individual weaknesses of cardiovascular system of otherwise pretty healthy human may lower the LD dose, and even non-letal but large dose may put one down for a time. – permeakra Jul 29 '15 at 17:39
• @permeakra Indeed. Biochemistry and pharmacokinetics aside, I suspect the motor control side effects from this rate of coffee consumption would result in a self-limitation on intake well before reaching a fatal dosage. – hBy2Py Jul 29 '15 at 20:43