Question: how many mg of caffeine in a large dunkin donuts coffee?
Answer: According to one source, a small cup (10 oz) has 53 mg of caffeine, and a large cup (24 oz) contains 128 mg (13). That's almost as much caffeine as you find in other varieties of regular coffee. Bottom Line: A small cup of coffee from Dunkin Donuts contains 215 mg of caffeine, while a single espresso contains 75 mg.