A standard 8-ounce cup of brewed coffee contains roughly 95 to 200 mg of caffeine. That wide range exists because caffeine content depends on the type of bean, how finely it’s ground, and the brewing method. Here’s what you can expect from every common way coffee is made.
Drip-Brewed Coffee
A typical home-brewed or diner-style drip coffee lands between 95 and 200 mg of caffeine per 8-ounce cup. The variation comes down to how much ground coffee you use, the grind size, and the bean itself. A heaping scoop of finely ground coffee will push you toward the higher end, while a lighter ratio brings you closer to 95 mg.
Grind size has a surprisingly large effect. Researchers found that finer grounds extract more caffeine regardless of brew time. In one experiment, grinding beans for 40 seconds instead of 10 doubled the caffeine in the finished cup, because the smaller particles exposed more surface area to the water. If you grind your own beans, this is one of the biggest levers you have over your caffeine intake.
Espresso
A single espresso shot contains about 63 to 64 mg of caffeine in just one ounce of liquid. Ounce for ounce, that’s roughly five times more concentrated than drip coffee. But because the serving size is so small, a single shot actually delivers less total caffeine than a full mug of drip.
Most espresso-based drinks at coffee shops use two shots (a doppio), which brings the total to about 150 mg. A latte, cappuccino, or flat white all start with the same espresso base, so the caffeine is essentially the same across those drinks. The milk doesn’t change the caffeine content.
Cold Brew
Cold brew is steeped for 12 to 24 hours, which produces a concentrate containing 100 to 200 mg of caffeine per 6-ounce serving before dilution. Most people (and most coffee shops) dilute the concentrate with water or milk at roughly a 1:1 ratio, which brings the final caffeine content into the same neighborhood as regular drip coffee. If you’re drinking undiluted cold brew concentrate, though, you could be getting significantly more caffeine than you’d expect.
Instant Coffee
Instant coffee is the lightest option. A single teaspoon of instant granules contains about 30 to 35 mg of caffeine. A standard prepared cup, using the recommended serving of about 2 grams, typically delivers 40 to 70 mg. That’s roughly half to two-thirds the caffeine of a drip-brewed cup, which makes instant a reasonable choice if you’re trying to cut back without going fully decaf.
Decaf Coffee
Decaf is not caffeine-free. An 8-ounce cup still contains about 7 mg of caffeine on average. That’s a small enough amount that most people won’t notice it, but if you’re highly sensitive to caffeine or drinking several cups of decaf per day, the milligrams add up.
What You’ll Get at Coffee Shops
Coffee chains tend to serve larger portions than the standard 8-ounce “cup” used in nutrition references, so the caffeine totals can be much higher than you’d assume. A Starbucks grande (16 oz.) brewed coffee contains 315 to 390 mg of caffeine, and a venti (20 oz.) ranges from 390 to 490 mg. Even a tall (12 oz.) starts at 235 mg.
Dunkin’ runs a bit lower. A medium (14 oz.) brewed coffee has about 210 mg, and a large (20 oz.) has 270 mg. Specialty drinks vary widely: a Starbucks grande latte or cappuccino has about 150 mg (two espresso shots), while a grande Coffee Frappuccino has 95 mg. A Dunkin’ medium latte contains about 166 mg.
The practical takeaway: a single large coffee-shop drink can account for most or all of your daily caffeine budget.
Arabica vs. Robusta Beans
The species of coffee bean matters more than most people realize. Arabica beans, which account for the majority of specialty and grocery-store coffee, contain about 1 to 1.5% caffeine by dry weight. Robusta beans contain roughly 2 to 3%, nearly double. Robusta is commonly used in instant coffee, some espresso blends, and many commercial-grade coffees. If your coffee tastes notably bitter and punchy, there’s a good chance it includes Robusta, and you’re getting more caffeine per cup.
Do Light and Dark Roasts Differ?
The difference is smaller than coffee-shop lore suggests. Dark roasting does break down a small amount of caffeine, but studies show the gap is negligible in practice. One 2018 analysis found that a serving of light roast contained about 60 mg of caffeine compared to 51 mg for the same amount of dark roast. That’s a minor difference that could easily vary between batches.
There is one quirk worth knowing. Dark roast beans puff up during roasting and become less dense. If you measure coffee by the scoop (volume), you’ll use slightly fewer grounds with dark roast and end up with marginally less caffeine. If you measure by weight on a kitchen scale, the caffeine content comes out nearly identical between roasts.
How Much Is Safe Per Day
The FDA sets the general guideline at 400 mg of caffeine per day for healthy adults. That works out to roughly two to three 12-ounce cups of brewed coffee, or four to five shots of espresso. At that level, caffeine is not associated with dangerous or negative health effects for most people. Pregnant individuals, people with heart conditions, and those on certain medications typically need to stay well below that threshold.
For quick reference, here’s a side-by-side comparison of common options:
- Drip coffee (8 oz.): 95–200 mg
- Espresso (1 oz. single shot): 63–64 mg
- Cold brew diluted (8 oz.): roughly 100–150 mg
- Instant coffee (8 oz.): 40–70 mg
- Decaf (8 oz.): about 7 mg