Caffeine looks different per serving versus per ounce. This comparison shows both, which explains why a small espresso feels strong.
| Drink | Per serving | Per ounce |
|---|---|---|
| Espresso | 63 mg (1 oz) | 63 mg |
| Cold brew | 150 mg (8 oz) | 19 mg |
| Brewed coffee | 95 mg (8 oz) | 12 mg |
| Energy drink | 80 mg (8 oz) | 10 mg |
| Black tea | 47 mg (8 oz) | 6 mg |
| Green tea | 28 mg (8 oz) | 3.5 mg |
| Cola | 35 mg (12 oz) | 3 mg |
Serving size matters. Espresso is the most concentrated per ounce, but the small serving means a single shot has less total caffeine than a mug of drip coffee.
See the Caffeine Content Chart and the Caffeine Calculator.