The caffeine content in a cup of coffee depends on the type of bean used to brew it, as well as the type of coffee drink you choose to drink, from a regular brew, to espresso, and instant to decaf.
Caffeine in Coffee
The exact amount of caffeine in a cup of coffee will vary depending on how strong you make it, although you’ll typically get about 95 milligrams from an eight-ounce freshly brewed cup, on average.
If you prefer lighter roasts of coffee, you will get more caffeine in your eight-ounce cup than a darker roast. Even though darker roasts tend to have a deeper flavor, that is irrelevant to they're caffeine content.
There is also a big difference when it comes to the beans used. Regardless of the lightness or darkness of the coffee, if you brew a cup of Arabica coffee beans, you may not get as much bang for your buck as a cup of Robusta coffee beans. On average, a cup of coffee brewed from Arabica could contain 84 to 580 milligrams of caffeine, compared to 232 to 800 milligrams from Robusta.
Espresso, Instant and Decaf
There is also a caffeine difference between regular brews, espresso, instant coffee and decaf coffee.
If you make regular instant coffee, you’ll get between 30 and 90 milligrams of caffeine in an eight ounce cup, depending on the brand and type of coffee.
On those days when you need that extra kick and add a shot of espresso to your coffee, you’ll pack in another 62.5 milligrams of caffeine from just one ounce.
You’ll even get a small amount of caffeine from decaf coffee. One cup of decaf can have close to seven milligrams of caffeine, though the average is three milligrams.
While everyone is different and you may be able to handle more caffeine than others, according to the 2015-2020 Dietary Guidelines, you should never have more than 400 milligrams in a day.
It’s perfectly fine to have some caffeine in your diet, but too much caffeine can affect your heart rhythm, make you dizzy, give you a headache or heartburn, and make you dehydrated.
Be aware of some of the side effects, and moderate your caffeine intake if any of them start to negatively impact you.