Starbucks lists caffeine per drink which I think is a good universal reference point. 400mg is 20oz, i.e. a Venti, http://www.starbucks.com/menu/drinks/brewed-c

Starbucks lists caffeine per drink which I think is a good universal reference point. 400mg is 20oz, i.e. a Venti, http://www.starbucks.com/menu/drinks/brewed-coffee/pikes-place-roast?foodZone=9999#size=121965 http://www.starbucks.com/menu/drinks/brewed-coffee/pikes-pla... .