title_body: Roughly how strong is one shot of espresso compared to a cup of drip coffee?
upvoted_answer: Caffeine content can vary a lot between different brewing methods and coffee beans used.
  
  according to How Much Caffeine is in a Cup of Coffee?:
  
  
    Brewed Coffee (8 oz / 237 mL): 95-200 mg of caffeine
    Espresso (1 oz / 30 mL): 47-75 mg of caffeine  
  
  
  That would mean your 12oz cup contains 143-300mg, and you'd need 2 to 6 espresso shots for the same amount, or 3.6 when comparing averages. (Which, personally, would make me feel rather trippy)