A 12-ounce cup of home-brewed coffee contains roughly 140 to 180 mg of caffeine. That number comes from scaling up the well-established baseline of 96 mg per 8-ounce cup, but in practice, your actual intake depends on the beans, the roast, and especially where the coffee comes from. A 12-ounce Starbucks Pike Place, for example, packs 235 mg, while the same size from Dunkin’ runs closer to 180 mg for a 10-ounce small.
Caffeine by Coffee Type at 12 Ounces
Not all 12-ounce coffees are created equal. Brewed drip coffee delivers the most caffeine per ounce of any standard preparation, but espresso-based drinks dilute their caffeine with milk and water. Here’s how popular 12-ounce (Tall) Starbucks drinks compare:
- Blonde Roast: 270 mg
- Pike Place (medium roast): 235 mg
- Nitro Cold Brew: 215 mg
- Dark Roast: 195 mg
- Cold Brew: 155 mg
- Americano: 150 mg
- Iced Coffee: 120 mg
- Caffè Mocha: 95 mg
- Latte, Cappuccino, or Macchiato: 75 mg
- Frappuccino: 65 mg
- Decaf brewed: 20 mg
The gap between a blonde roast brewed coffee (270 mg) and a latte (75 mg) is enormous, even though they’re the same volume. That’s because a 12-ounce latte only contains one or two shots of espresso at about 63 mg each, with the rest being steamed milk. A brewed coffee is concentrated coffee from top to bottom.
Why Home-Brewed Coffee Varies So Much
If you brew at home, the caffeine in your cup depends on three main factors: how much ground coffee you use, the type of bean, and your water temperature. Using more grounds per cup or letting them steep longer both increase extraction. Water between 90°C and 100°C (about 195 to 212°F) pulls the most caffeine from the grounds, so a full-boil pour-over will extract more than a lukewarm brew.
Bean variety matters more than most people realize. Arabica beans, which make up the majority of specialty and grocery store coffee, contain 1.2 to 1.5% caffeine by dry weight. Robusta beans nearly double that at 2.2 to 2.7%. If your coffee blend includes Robusta (common in instant coffee and some espresso blends), your 12-ounce cup could easily push past 200 mg even at home.
Light Roast vs. Dark Roast
There’s a persistent belief that dark roasts are “stronger” in caffeine, but the opposite is slightly true. Roasting breaks down a small amount of caffeine, so light roasts retain a bit more. One study found light roast brewed coffee contained about 60 mg per serving compared to 51 mg for the same amount of dark roast. That said, the difference is small enough to be negligible in everyday drinking.
The more practical issue is how you measure your coffee. Dark roast beans puff up during roasting, so a scoop of dark roast by volume contains fewer beans (and less caffeine) than the same scoop of denser light roast beans. If you measure by weight instead of scoops, the caffeine content between roasts is nearly identical.
Decaf Isn’t Caffeine-Free
A 10- to 12-ounce cup of decaf brewed coffee still contains 7 to 8 mg of caffeine on average. That’s a tiny fraction of a regular cup, but it’s not zero. If you’re highly sensitive to caffeine or drinking several cups of decaf a day, it can add up. Starbucks decaf runs higher at about 20 mg per 12-ounce Tall.
How 12 Ounces Fits Into Daily Limits
The FDA considers up to 400 mg of caffeine per day safe for most healthy adults. The agency specifically describes that as “about two to three 12-fluid-ounce cups of coffee.” So a single 12-ounce cup of home-brewed coffee uses up roughly a third to half of that budget, depending on strength. A Starbucks Blonde Roast Tall gets you to nearly 70% of the daily limit in one drink.
If you’re combining coffee with tea, energy drinks, or chocolate throughout the day, it’s worth knowing that your morning 12-ounce cup likely contributes 140 to 270 mg right out of the gate, leaving less room than you might expect for the rest of the day.