Close, but not exactly zero. A plain 8 fl oz cup of black brewed coffee has about 2 calories, and 100g of it lands at roughly 1 calorie. USDA FoodData Central puts brewed coffee at 1 calorie per 100g, which is basically water plus a trace of protein and dissolved solids. Nutrition labels round anything under 5 calories per serving down to zero, so "zero calories" on a menu is accurate enough. It is only true while the cup stays black. The source: USDA-based brewed coffee data via NutritionValue.
Why black coffee is not literally zero
Coffee is about 98 to 99 percent water once it is brewed. What is left is a small amount of dissolved plant material: acids, oils, a trace of protein, and tiny amounts of carbohydrate. Per 100g, USDA lists brewed coffee at 1 calorie, with 0.13g protein, 0g carbs, and 0.02g fat. Scale that to a standard 8 fl oz cup (240g) and you get about 2 calories total. A 12 fl oz cup lands near 3.
So the honest answer is that black coffee carries a rounding-error amount of calories. For any diet or fasting purpose it behaves like zero, but it is not a true zero the way plain water is. Espresso runs a little higher because it is more concentrated: USDA puts restaurant espresso at 9 calories per 100g, which works out to roughly 3 calories for a single shot and 5 for a double. Decaf tracks the same as regular black coffee, near 0 to 2 calories a cup, since removing caffeine does not add anything. More on that in our decaf breakdown.
Brewing method barely moves the number either. Drip, pour over, French press, and cold brew all land in the same 0 to 5 calorie range per cup when served black, because you are still drinking mostly water with a trace of dissolved solids. Cold brew can taste sweeter and heavier, but that is flavor, not calories. Our cold brew guide covers where it does differ, which is caffeine.
The "zero calories" you see on a coffeehouse menu comes from labeling rules. In the United States, anything under 5 calories per serving can be listed as zero. Black coffee clears that bar with room to spare, so a plain brewed coffee, an Americano, or an espresso shot all show up as effectively calorie-free. Compare that to the built drinks on the same board, where the milk and syrup do all the work. See the Starbucks menu breakdown for how those stack up.
The calories only show up when you build the drink. That is where a "zero calorie" coffee turns into a 200-plus calorie one.
Calories in the cup, black vs built
| Drink | Serving | Approx. calories | Source |
|---|---|---|---|
| Black brewed coffee | 8 fl oz | 2 | USDA |
| Black brewed coffee | 12 fl oz | 3 | USDA |
| Decaf brewed coffee | 8 fl oz | 0 to 2 | USDA |
| Espresso, single shot | 1 fl oz | ~3 | USDA |
| Espresso, double shot | 2 fl oz | ~5 | USDA |
| Add: 1 tsp granulated sugar | 4g | 16 | USDA |
The pattern is clear. The coffee itself is a rounding error. One teaspoon of sugar (16 calories) already outweighs the entire cup underneath it, and most people use two or three. Milk stacks on top of that, and flavored syrups more again. A large milk-and-syrup coffeehouse drink can clear 200 to 400 calories, almost none of which comes from the coffee. If you want to see how fast a built drink climbs, look at the almond milk latte calorie math and the sugar in Starbucks drinks rundown.
For context, the FDA cites 400mg of caffeine a day as an amount generally not associated with negative effects in healthy adults. How caffeine affects you depends on your own tolerance and health, so treat these numbers as information, not advice.
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FAQ
Does black coffee break a fast?
At about 2 calories a cup, plain black coffee is generally treated as fasting-safe. It is the milk, sugar, and syrups that add real calories and can break a fast, not the coffee itself.
How many calories are in a cup of black coffee?
Roughly 2 calories for an 8 fl oz cup and about 3 for a 12 fl oz cup, based on USDA data of 1 calorie per 100g of brewed coffee.
Does espresso have more calories than drip coffee?
Slightly. USDA lists espresso at 9 calories per 100g because it is concentrated, so a single shot is about 3 calories. Still negligible until you add milk or sugar.