Beverages
Coffee
Overview
Why drink coffee?
Black brewed coffee is essentially calorie-free, at about 2 kcal per 8-ounce cup, yet it delivers caffeine, a little riboflavin and potassium, and a range of plant compounds from the roasted bean. It counts toward your daily fluids, and regular moderate drinking is linked to favorable health patterns in large population studies.
Good to know: Caffeine adds up quickly, so most adults are advised to stay under about 400 mg a day, and late-afternoon cups can disrupt sleep; cream, sugar and syrups turn a 2-calorie drink into a substantial one.
Alertness without calories
Each 8-ounce cup supplies about 95 mg of caffeine, which blocks drowsiness signals in the brain and can sharpen focus, reaction time and perceived energy.
Surprising riboflavin
One cup provides 0.18 mg of riboflavin, 14% of the Daily Value, a B vitamin your cells use to turn food into usable energy.
Hydration and a little potassium
Coffee is mostly water and contributes 116 mg of potassium per cup, a mineral that supports normal fluid balance, nerve signaling and muscle contraction.
Overview drafted with AI from USDA FoodData Central figures. For education, not medical advice.
Nutrition facts
What’s in coffee?
Calories
1kcal
Protein
0.12g
Carbs
0g
Fat
0.02g
Fiber
0g
Sugars
0g
Minerals
- Calcium2 mg0%
- Iron0.01 mg0%
- Magnesium3 mg1%
- Phosphorus3 mg0%
- Potassium49 mg1%
- Sodium2 mg0%
- Zinc0.02 mg0%
- Copper<0.01 mg0%
Vitamins
- Vitamin E0.01 mg0%
- Vitamin K0.1 µg0%
- Thiamin (B1)0.01 mg1%
- Riboflavin (B2)0.08 mg6%
- Niacin (B3)0.19 mg1%
- Vitamin B6<0.01 mg0%
- Folate2 µg1%
Other compounds
- Caffeine40 mg
% Daily Value is based on FDA reference amounts for adults. Bars cap at 100%.
People asked
Questions about coffee
Keep exploring
More Beverages
Source: USDA FoodData Central, “Beverages, coffee, brewed, prepared with tap water” (SR Legacy, FDC ID 171890).View the USDA record ↗ (opens in a new tab).