This question is interesting. So we can easily know whether or not we are overdoing our daily caffeine dose. It depends a lot on how we prepare the coffee:
a cup of brewed coffee (24cl) contains approximately 70-140 mg of caffeine
A 30-50 ml cup of espresso contains approximately 63 mg of caffeine.
contains less caffeine, about 30-80mg (one or two tablespoons of coffee)
Decaffeinated coffee: contains less than 10mg of caffeine per cup.
And what will be the degree of caffeine if you go to Starbucks for a cup of coffee:
Short: 180 mg caffeine
Tall: 260mg caffeine
Large: 330 mg caffeine
Venti: 415 mg of caffeine