Coffee generally contains about twice as much caffeine as tea per cup. A typical 8-ounce cup of brewed coffee has between 95 and 200 milligrams of caffeine, while black tea ranges from about 14 to 70 milligrams, green tea from 24 to 45 milligrams, and white tea from 6 to 60 milligrams
. Interestingly, tea leaves actually contain more caffeine by weight than coffee beans-tea leaves have around 3.5% caffeine compared to 1.1–2.2% in coffee beans-but coffee is brewed in a way that extracts more caffeine into the cup, making the beverage stronger in caffeine content
. The variation in caffeine content depends on factors such as the type of coffee bean (Robusta has more caffeine than Arabica), the tea variety, harvest time, and brewing method. Coffee is brewed at higher temperatures and for longer, which extracts more caffeine than steeping tea leaves
. In summary:
- Coffee: 95–200 mg caffeine per cup
- Black tea: 14–70 mg caffeine per cup
- Green tea: 24–45 mg caffeine per cup
- White tea: 6–60 mg caffeine per cup
Thus, coffee delivers roughly double the caffeine of black tea per serving, with tea providing a gentler, more sustained caffeine effect due to compounds like L-theanine
