Coffee Bean Caffeine Content

by Roger Thorne

Coffee has been a popular drink for centuries, likely due in no small part to the presence of caffeine, a natural stimulant. Each coffee bean contains a small amount of caffeine in it, and once the coffee is processed and turned into a drink, that caffeine remains.

Caffeine by Type

According to Lecturer of health education Tommy K. Begay, Jr., MPH, CHES, at the University of Arizona, coffee beans are composed of between one and two percent caffeine, depending on the kind of bean. There are two main types of coffee bean: arabica and robusta. The arabica bean has a caffeine content of about one percent, while the robusta bean has about two percent caffeine. Some coffees are composed of entirely one type of bean or the other, while many others mix the two types in different amounts.

Caffeine and Coffee

Of course, few people get coffee caffeine by eating the bean directly. Most people get their coffee in liquid form after it has been roasted, ground and had water added to make the popular drink. An average, 12-ounce brewed cup of coffee has between around 260 milligrams of caffeine, while an average 2-ounce espresso has around 120 milligrams of caffeine.

Caffeine per Bean

If you're a stickler for figures, you can guess that a single coffee bean contains about 2 milligrams of caffeine, give or take. There are about 4,000 coffee beans to a pound, according to One pound is equal to about 454 grams, which means that each bean weighs approximately .114 grams, or 114 milligrams. This means that each 114 milligrams coffee bean is composed of between about 1.14 to 2.28 milligrams of caffeine.

Effects of Caffeine

The side effects of coffee are generally harmless for most people and include increased wakefulness, improved concentration and reduced fatigue. However, getting too much caffeine can cause negative side effects as well. Harvard School of Public Health states that the upper caffeine limit for most people is 600 milligrams daily. Too much caffeine could result in irritability, upset stomach, insomnia, muscle tremors and even elevated heartbeat.

Photo Credits:

  • coffee,coffee beans and casserole image by Maria Brzostowska from

This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or