what is a deadly amount of caffeine
How much is too much? Up to 400 milligrams (mg) of caffeine a day appears to be safe for most healthy adults. That's roughly the amount of caffeine in four cups of brewed coffee, 10 cans of cola or two energy shot drinks. Keep in mind that the actual caffeine content in beverages varies widely, especially among energy drinks. Although caffeine use may be safe for adults, it's not a good idea for children.