Coffee varies. I've long understood that a normal (8 ounce, ish) cup of drip coffee averages around 100mg of caffeine[0].

Java Monster Triple Shot Mocha comes in a can, and has 300mg of caffeine per can[1][2].

This seems to suggest that getting the equivalent of 3 cups of coffee in one can is, in fact, a thing that people can accomplish.

[0]: https://www.aboutcoffee.org/beans/decaf-coffee/ https://ific.org/resources/toolkits/caffeine/ https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...

[1]: https://www.monsterenergy.com/en-ca/energy-drinks/java-monst...

[2]: And they're delicious