Part of our Mushroom Coffee guide library.
Short answer: An 8-ounce cup of brewed coffee has about 95 mg of caffeine, and a 12-ounce cup typically has 113 to 247 mg. A 1-ounce shot of espresso has about 63 mg, a 6-ounce cup of instant coffee about 47 mg, and an 8-ounce cup of decaf about 2 to 15 mg. Coffee-shop drinks vary a lot: in one study, the same 16-ounce coffee from the same shop ranged from 259 to 564 mg over six days. For most healthy adults, the FDA cites up to 400 mg a day, or about two to three 12-ounce cups, as an amount not generally linked to negative effects.
The caffeine in "a cup of coffee" depends on the cup size, the beans and how the coffee is made. Here are typical amounts for brewed coffee, espresso, instant and decaf, how coffee compares with tea and matcha, why the numbers vary so much, and how much is too much.
What you'll learn
- How much caffeine is in brewed coffee, espresso, instant and decaf
- How coffee compares with tea, matcha and mushroom coffee
- Why the caffeine in your cup can vary so much
- How much coffee is too much, and who should be careful
Caffeine in coffee at a glance
| Drink | Serving | Typical caffeine | Source |
|---|---|---|---|
| Brewed coffee | 8 fl oz | About 95 mg | USDA FoodData Central |
| Brewed coffee | 12 fl oz | 113–247 mg | FDA |
| Coffee-shop brewed coffee | 16 fl oz | 58–259 mg in one study (average 188 mg) | McCusker et al., 2003 |
| Espresso | 1 fl oz (single shot) | About 63 mg | USDA FoodData Central |
| Instant coffee | 6 fl oz | About 47 mg | USDA FoodData Central |
| Decaf coffee | 8 fl oz | 2–15 mg | FDA |
| Decaf espresso | 1 shot | 3–16 mg in one study | McCusker et al., 2006 |
A double shot of espresso is two single shots, so roughly twice the caffeine of one shot. Most coffee-shop drinks are larger than 8 ounces, so check the size before you compare.
How much caffeine is in a shot of espresso?
About 63 mg in a 1-ounce single shot (USDA FoodData Central). Espresso is much more concentrated than drip coffee ounce for ounce, but a single shot usually has less caffeine than a full mug of brewed coffee, because the serving is so much smaller. Lattes and cappuccinos get their caffeine from the espresso shots, so a latte with two shots has about as much caffeine as two shots.
How coffee compares with tea, matcha and mushroom coffee
| Drink | Serving | Typical caffeine | Source |
|---|---|---|---|
| Brewed coffee | 12 fl oz | 113–247 mg | FDA |
| Black tea | 12 fl oz | About 71 mg | FDA |
| Green tea | 12 fl oz | About 37 mg | FDA |
| Matcha | 2 g of powder | About 28–70 mg | Meyer et al., 2023 |
| NeuroCoffee (mushroom coffee) | 2 tbsp | 30 mg | Product Facts |
| NeuroMatcha (mushroom matcha) | 2 tbsp | 17.64 mg | Product Facts |
For more detail, see does matcha have caffeine?, does mushroom coffee have caffeine? and matcha vs coffee.
Why the caffeine in your cup varies
- Cup size. The biggest factor. A 16- or 20-ounce coffee-shop cup can hold two or more 8-ounce servings.
- The coffee itself. Robusta beans contain more caffeine than Arabica: in one analysis of green beans, Robusta averaged 2.9% caffeine by dry weight versus 1.8% for Arabica (Adnan et al., 2020). For more, see Arabica vs Robusta.
- How it is made. The amount of coffee used and how strong it is brewed change the result.
- Batch to batch. Even the same drink varies. In a U.S. study, a 16-ounce coffee bought from the same coffee shop on six consecutive days ranged from 259 to 564 mg (McCusker et al., 2003).
Restaurants and coffee shops are not required to tell you how much caffeine their drinks contain, but packaged foods must list caffeine as an ingredient when it is added, and many products state the amount voluntarily (FDA).
Does decaf coffee have caffeine?
Yes, a little. Decaf typically has 2 to 15 mg in an 8-ounce cup (FDA). In one study, decaf coffees from coffee shops contained 0 to 13.9 mg per 16-ounce serving, and decaf espresso 3 to 16 mg per shot (McCusker et al., 2006). If you need to avoid caffeine completely, decaf is not caffeine-free.
How much coffee is too much?
For most healthy adults, the FDA cites 400 mg of caffeine a day, about two to three 12-ounce cups of coffee, as an amount not generally associated with negative effects. People vary widely in how sensitive they are and how fast they clear caffeine, and some medical conditions and medications make people more sensitive (FDA).
Signs you may be having too much include a fast heart rate or palpitations, trouble sleeping, anxiety, jitters, an upset stomach, nausea and headaches (FDA). Rapidly consuming around 1,200 mg, less than half a teaspoon of pure caffeine powder, can cause toxic effects such as seizures (FDA).
If you are pregnant, trying to become pregnant or breastfeeding, the FDA recommends asking your health care provider whether you should limit caffeine (FDA).
How to cut back on caffeine
- Go smaller or switch one cup a day to half-caf or decaf.
- Cut back gradually. Caffeine withdrawal is not dangerous but can be unpleasant (FDA).
- Try a lower-caffeine drink such as green tea, matcha or a mushroom coffee blend; see why caffeine crashes happen.
- Count every source, including tea, soda, energy drinks and chocolate.
Common myths (quick reality check)
Myth: Espresso has more caffeine than regular coffee. Reality: Ounce for ounce, yes. Per drink, usually not: a single shot has about 63 mg, while an 8-ounce cup of brewed coffee has about 95 mg.
Myth: Decaf is caffeine-free. Reality: Decaf typically still has 2 to 15 mg in an 8-ounce cup.
Myth: A cup of coffee is always about 95 mg. Reality: That is for 8 ounces of brewed coffee. Coffee-shop cups are often larger, and the same drink can vary widely from day to day.
Frequently asked questions (FAQ)
How much caffeine is in a cup of coffee?
About 95 mg in an 8-ounce cup of brewed coffee, and typically 113 to 247 mg in a 12-ounce cup. Coffee-shop drinks can be higher.
How much caffeine is in a shot of espresso?
About 63 mg in a 1-ounce single shot. A double shot has roughly twice that.
Does espresso have more caffeine than coffee?
Per ounce, yes. Per serving, a single shot of espresso usually has less caffeine than an 8-ounce cup of brewed coffee.
How much caffeine is in decaf coffee?
Typically 2 to 15 mg in an 8-ounce cup. Decaf is lower in caffeine, not caffeine-free.
How many cups of coffee a day is safe?
For most healthy adults, up to 400 mg of caffeine a day, about two to three 12-ounce cups, is not generally linked to negative effects. People who are sensitive, pregnant or taking certain medications may need less.
Does instant coffee have less caffeine than brewed?
Usually a little less per cup. A 6-ounce cup of instant coffee has about 47 mg, though it depends on how much powder you use.
Why does my coffee-shop coffee feel stronger some days?
It may really be stronger. In one study, the same 16-ounce coffee from the same shop ranged from 259 to 564 mg of caffeine over six days.
Related guides
- Why does coffee make you poop?
- Does mushroom coffee have caffeine?
- Does matcha have caffeine?
- Matcha vs coffee
- Arabica vs Robusta: choosing the coffee base
- Why caffeine crashes happen
Disclaimer and when to seek help
This article is for general education and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure, or prevent any disease. Talk to your health care provider about caffeine if you are pregnant, trying to become pregnant or breastfeeding, have a heart condition, anxiety or high blood pressure, or take medication.
References
- U.S. Food and Drug Administration. "Spilling the Beans: How Much Caffeine Is Too Much?" Content current as of August 28, 2024.
- U.S. Department of Agriculture, Agricultural Research Service. FoodData Central: brewed coffee (FDC 171890), espresso (FDC 171891), instant coffee (FDC 174130), decaffeinated brewed coffee (FDC 171889).
- McCusker RR, Goldberger BA, Cone EJ. "Caffeine content of specialty coffees." Journal of Analytical Toxicology, 2003;27(7):520-522. doi:10.1093/jat/27.7.520
- McCusker RR, et al. "Caffeine content of decaffeinated coffee." Journal of Analytical Toxicology, 2006;30(8):611-613. doi:10.1093/jat/30.8.611
- Adnan A, et al. "Reliable Discrimination of Green Coffee Beans Species: A Comparison of UV-Vis-Based Determination of Caffeine and Chlorogenic Acid with Non-Targeted Near-Infrared Spectroscopy." Foods, 2020;9(6):788. doi:10.3390/foods9060788
- Meyer BR, et al. "Catechin composition, phenolic content, and antioxidant properties of commercially-available bagged, gunpowder, and matcha green teas." Plant Foods for Human Nutrition, 2023;78(4):662-669. doi:10.1007/s11130-023-01121-2
