A typical 8-ounce (oz) cup of brewed coffee contains approximately 95 to 165 milligrams (mg) of caffeine, with an average around 100 to 120 mg depending on brewing time and coffee type
. However, many coffee servings are larger than 8 oz-for example, a 12 oz cup at Starbucks can contain roughly 168 to 246 mg or more of caffeine
. The caffeine content varies based on several factors:
- Type of coffee bean: Robusta beans have about twice the caffeine of Arabica beans, which are more commonly used
- Brewing method: Brewed coffee generally has more caffeine per serving than espresso, but espresso has a higher caffeine concentration per ounce. A typical 1 oz shot of espresso contains about 40–67 mg of caffeine
- Serving size: Larger cups contain proportionally more caffeine. For example, 12 oz brewed coffee has about 113 to 247 mg caffeine
- Grind size and brewing time: Finer grind and longer contact with water increase caffeine extraction
- Roast level: Roasting has minimal effect on caffeine content; darker roasts lose a small amount but the difference is minor
Other coffee types have different caffeine amounts, for example:
- Instant coffee (8 oz): about 63 mg caffeine
- Decaffeinated coffee (8 oz): 2 to 5 mg caffeine
- Latte or mocha (8 oz): 63 to 126 mg caffeine
In summary, an average cup of brewed coffee (8 oz) contains roughly 95–165 mg of caffeine, but actual caffeine intake depends on cup size, coffee type, and preparation method
