The amount of caffeine in foods and beverages varies widely. The brand of
coffee or tea,
how it is prepared, the type of beans or leaves used, and the style of serving (espresso, latte and others) also affect caffeine content. In general, brewed coffee contains the highest amounts of caffeine, with an average of 137 mg per 8-ounce cup (2). Instant coffee contains about 76 mg per 8-ounce cup (2). A 12-ounce can of caffeinated soda contains about 37 mg (2).