How much coffee is too much coffee?

It is common knowledge that students will turn to drinking coffee in order to stimulate their senses and to stay awake. The fact that there are many coffee shops that are easily accessible makes it hard to stray away from buying a cup. It may begin to be dangerous depending on how much people have built up their tolerance. Some people are able to tolerate a higher dose than others. It is said that, for the average adult, consuming 4 cups of coffee, which is roughly 400mg of caffeine, is a safe amount (healthline.com). On the other hand, going over that number in a short period of time may lead to symptoms such as, restlessness, insomnia and increased heart palpitations (healthline.com).