Many people seem to think that a 0.85oz shot of espresso has the same amount of caffeine as a cup of coffee. Is there any validity to this?
According to caffeineinformer, there is 77 mg of caffeine in 1½ shots of espresso.
Comparatively, an 8 oz. cup of brewed coffee comes in at 163 mg of caffeine.
There is roughly 1/2 as much caffeine in 1.5 shots as there is in 8 oz. of brewed coffee.
It varies by size, bean origin, roast method and other factors, the caffeine content of "typical" servings of espresso vs. drip brew are 53 mg vs. 95 to 200 mg. Source: Wikipedia.
In example, in Starbucks Expresso it's around 150mg.
Here is full table according to Wikipedia:
And here is a full list according to Center for Science in the Public Interest: