"[UK] Consumer group Which? measured the caffeine in cappuccino, espresso and filter coffee at Caffè Nero, Costa, Greggs, Pret a Manger and Starbucks. It found Pret's single espresso had six times as much caffeine as Starbucks's. A Starbucks cappuccino contained the least at 66mg - less than the 75mg in a single tea bag"
https://www.youtube.com/watch?v=etnMr8oUSDo