How Much Caffeine Is in a Cup of Coffee?
An 8-ounce cup of brewed coffee averages about 96 mg of caffeine, but cup size, brew method and the beans themselves can push your real number far lower or higher. About a 7-minute read.
An 8-ounce cup of brewed coffee has about 96 mg of caffeine, according to Mayo Clinic. Real cups vary a lot. The FDA puts a 12-ounce cup of regular brewed coffee at 113 to 247 mg, a 1-ounce shot of espresso has about 63 mg, and decaf usually has 2 to 15 mg per 8 ounces. Cup size and how much coffee you use per cup matter most.
You want a number. Maybe you're counting toward a daily limit, maybe your afternoon café cup keeps you up at night, or maybe you just wonder why one mug wakes you up and another barely registers.
The commonly quoted figure is about 96 mg of caffeine in an 8-ounce cup of brewed coffee. That is a useful average, and it hides a wide range. The size of your mug, the amount of ground coffee in it, the brew method and the beans all move the total.
This lesson gives you the standard numbers by brew method, explains why they vary, and shows you how to estimate the caffeine in the cup you actually drink.
How much caffeine is in a cup of coffee?
An 8-ounce (237 mL) cup of brewed coffee has about 96 mg of caffeine, according to Mayo Clinic. The National Coffee Association, citing USDA data, gives 12 to 16 mg per ounce of brewed coffee, which works out to about 96 to 128 mg for 8 ounces. Larger cups scale up from there.
The FDA's figure for a 12-ounce cup of regular brewed coffee is 113 to 247 mg. That wide range is the honest answer. Two 12-ounce coffees from two different kitchens or cafés can differ by more than 100 mg.
Researchers have the same problem. A 2014 study in Food & Function by Ludwig and colleagues measured coffees bought in Scotland, Italy and Spain and found such large differences in serving size and caffeine that the authors argued "one cup of coffee" isn't a reproducible unit of measurement at all.
How much caffeine is in coffee by brew method?
Drip and pour-over coffee land around 96 mg per 8 ounces. A single 1-ounce espresso has about 63 mg, and instant coffee about 62 mg per 8 ounces. Café drinks built on espresso, like Americanos and lattes, often carry 100 mg or more. Decaf usually has 2 to 15 mg per 8-ounce cup.
| Drink | Serving | Caffeine (approx.) | Source |
|---|---|---|---|
| Brewed coffee (drip, pour-over) | 8 oz (237 mL) | 96 mg | Mayo Clinic |
| Brewed coffee, regular | 12 oz (355 mL) | 113 to 247 mg | FDA |
| Espresso | 1 oz (30 mL) shot | 63 mg | Mayo Clinic, USDA via NCA |
| Instant coffee | 8 oz (237 mL) | 62 mg | Mayo Clinic |
| Coffee-shop Americano | One serving | 143 mg average | Wierzejska and Gielecińska, 2024 |
| Coffee-shop latte | One serving | 97 mg average | Wierzejska and Gielecińska, 2024 |
| Decaf brewed coffee | 8 oz (237 mL) | 2 to 15 mg | FDA |
Café drink averages come from samples bought in Poland, so US chains may differ. Cold brew isn't listed because its caffeine depends heavily on the recipe and dilution.
Cold brew deserves a note. In a 2017 Scientific Reports study, Fuller and Rao found that coarse-ground cold brew steeped for 24 hours reached a higher caffeine concentration than hot coffee made at the same ratio: about 1,230 mg per liter versus 970 mg per liter for a medium roast. Most cold brew is made as a concentrate and then diluted, so the caffeine in your glass depends on how much water, milk or ice you add.
Why does caffeine vary so much from cup to cup?
The biggest factor is how much ground coffee goes into your cup, which depends on serving size and brew ratio. After that come the bean species, the brew method and, to a lesser degree, the roast. A big mug of strong coffee can easily carry twice the caffeine of a small, weak one.
Your "cup" may be bigger than you think
Nutrition tables usually use 8 ounces. The NCA's classic brewing ratio is written per 6 ounces of water: 1 to 2 tablespoons of ground coffee. Many home mugs and café sizes hold 12, 16 or 20 ounces. If you fill a 16-ounce travel mug, you're drinking two "cups" by the table's math, which is roughly 190 mg at the Mayo Clinic average.
Strength matters too. Using 2 tablespoons per 6 ounces instead of 1 roughly doubles the coffee, and so the caffeine, in the same volume of water.
Bean species and variety
Almost all specialty coffee is arabica. Robusta, common in some espresso blends and many instant coffees, naturally carries more caffeine. A few arabica varieties go the other way. Laurina, also called Bourbon Pointu, is known as a naturally low-caffeine variety.
Roast level and brew method
Roast level changes caffeine much less than people expect, and the direction depends on whether you measure by scoop or by weight. We cover that in detail in Lesson 04: does dark roast have more caffeine? Brew method matters mostly through contact time and ratio. Longer steeping and more coffee per ounce pull more caffeine into the cup.
How many cups of coffee is too much?
For healthy adults, the FDA cites 400 mg of caffeine a day as an amount not generally linked to negative effects. That's about four 8-ounce cups of brewed coffee at 96 mg each, or about two and a half 12-ounce café coffees at the top of the FDA's range. People who are pregnant should ask their health care provider.
Some people feel jittery or sleep poorly at much lower amounts. The FDA notes that sensitivity varies from person to person, and the agency recommends talking with a health care provider about caffeine if you're pregnant, trying to become pregnant or breastfeeding, or if you take medications or have a condition that caffeine might affect.
Coffee-shop drinks add up faster than home coffee. The 2024 Nutrients study by Wierzejska and Gielecińska found that coffees from chains carried more than three times the caffeine of homemade coffee, and that four to five servings of most café coffee types could pass 400 mg in a day. The authors suggested that advice like "three to five cups a day" should specify serving size and strength.
How can you estimate the caffeine in your own cup?
Measure your cup and use a per-ounce figure. For brewed coffee, multiply the ounces by 12 to 16 mg, the USDA range the NCA cites. For espresso drinks, count shots at about 63 mg each. Then adjust upward if you brew strong, or if the bag lists robusta.
- Fill your usual mug with water and pour it into a measuring cup to find its real size in ounces.
- For drip, pour-over or French press, multiply those ounces by 12 for a mild estimate and by 16 for a strong one. A 12-ounce mug comes out to about 144 to 192 mg.
- For espresso drinks, ask or count the shots. A double-shot latte has about 126 mg from the espresso. Milk adds no caffeine.
- For cold brew, check the label or your recipe. Concentrate that you dilute 1:1 carries roughly half its caffeine per ounce once mixed.
- Keep a quick daily tally if you're watching your total. Tea, soda, energy drinks and chocolate count too.
If you brew at home with a scale, our beginner brewing lesson shows simple ratios that make your strength, and your caffeine, more consistent from day to day.
How can you drink coffee with less caffeine?
Switch some cups to decaf, use a smaller mug, brew a little weaker or mix regular and decaf beans for half-caf. Decaf typically has 2 to 15 mg per 8 ounces, so swapping your afternoon cup can cut 80 mg or more. Naturally low-caffeine varieties are another option for people who want regular coffee flavor.
A few options from our catalog, with tasting notes as the roasters list them:
- Coffee Bros. Decaf Roast Coffee is a medium roast from Nariño, Colombia, decaffeinated with ethyl acetate from sugarcane. The roaster lists graham cracker and semi-sweet chocolate.
- Peace Coffee Decaf French Roast is a dark, water-process decaf from Honduras with toasted walnut, spice and caramelized sugar notes.
- Tayst Defiantly Decaf uses the Swiss Water process. Tayst describes it as rich, smooth and full-flavored.
- Onyx Coffee Lab Decaf Espresso Peru Norandino is a washed Peru for evening espresso, with chocolate, citrus and soft stone fruit listed.
- Hula Daddy Kona Coffee Bourbon Pointu Laurina is a Kona coffee from the low-caffeine Laurina variety. It isn't decaf, so it still has some caffeine.
Frequently asked questions
How much caffeine is in an 8 oz cup of coffee?
About 96 mg for brewed coffee, according to Mayo Clinic. USDA data cited by the National Coffee Association gives 12 to 16 mg per ounce, or about 96 to 128 mg for 8 ounces. Strong coffee or robusta blends can be higher.
How much caffeine is in a 12 oz or 16 oz coffee?
The FDA puts a 12-ounce cup of regular brewed coffee at 113 to 247 mg. Using the USDA's 12 to 16 mg per ounce, a 16-ounce coffee comes to about 192 to 256 mg. Café brews are often at the higher end.
How many cups of coffee equal 400 mg of caffeine?
About four 8-ounce cups of brewed coffee at roughly 96 mg each. With larger or stronger cups, you can reach 400 mg in two or three. The FDA cites 400 mg a day as generally safe for healthy adults.
Does cold brew have more caffeine than hot coffee?
It can. A 2017 study found coarse-ground cold brew reached a higher caffeine concentration than hot coffee made at the same ratio. Cold brew is usually a concentrate, though, so the caffeine in your glass depends on how much you dilute it.
Does decaf coffee have caffeine?
Yes, a little. The FDA says decaf typically has 2 to 15 mg in an 8-ounce cup, compared with about 96 mg for regular brewed coffee. If you need to avoid caffeine completely, talk with your health care provider.
Sources: U.S. Food and Drug Administration, Spilling the Beans: How Much Caffeine Is Too Much? (2024) · Mayo Clinic, Caffeine Content for Coffee, Tea, Soda and More (2025) · National Coffee Association, How to Make Espresso (2026) · Nutrients, Wierzejska and Gielecińska, Evaluation of the Caffeine Content in Servings of Popular Coffees (2024) · Scientific Reports, Fuller and Rao, Caffeine and Chlorogenic Acid in Cold Brew Coffee (2017) · Food & Function, Ludwig et al., Variations in Caffeine and Chlorogenic Acid Contents of Coffees (2014)