Coffee is a popular drink and probably the most common source of caffeine. The caffeine content of coffee can vary considerably depending on several factors, including the type, the brewing method, and the brand.
According to the Dietary Guidelines for Americans 2015–2020, more than 95 percent of adults in the United States consume foods and drinks containing caffeine. On average, U.S. adults consume between 110 and 260 milligrams (mg) of caffeine per day.
In this article, we examine the caffeine content of some different types and brands of coffee. We also cover factors that affect the caffeine content of coffee, other sources of caffeine, the recommended daily intake of caffeine, and its side effects.
Different types of coffee contain varying amounts of caffeine. We discuss the caffeine content of some of the most common types of coffee below:
Brewed coffee, which is also called filter coffee, involves brewing ground coffee beans in hot water. This mixture usually sits in a paper, metal, or plastic filter that separates the grounds from the brewed coffee.
People can make brewed coffee in a variety of ways, usually using a filter, a percolator, or a French press.
An 8-oz cup of brewed coffee typically contains around 95 mg of caffeine.
Despite its name, decaffeinated, or decaf, coffee still contains some caffeine. For instance, an average 8-oz cup of brewed decaf coffee contains around 2 mg of caffeine.
Cold brew coffee is different than iced coffee, which simply involves serving brewed coffee over ice. To make cold brew coffee, manufacturers steep the coffee grounds in water at room temperature for anywhere between 8 and 24 hours.
A 2017 study found that a 12-oz cup of cold brew coffee can contain between 153 mg and 238 mg of caffeine.
Making this type of coffee involves adding hot water to instant coffee powder or granules.
Instant coffee usually contains less caffeine than freshly brewed coffee. A typical 8-oz cup of regular instant coffee contains about 62 mg of caffeine.
Espresso is a strong coffee beverage that people make by forcing hot water or steam through very fine coffee grounds. Making espresso coffee involves the use of a machine or stovetop moka pot.
Espresso serving sizes are generally much smaller than those of brewed coffee because of the high caffeine content.
A single 1-oz shot of espresso contains approximately 63 mg of caffeine.
Many manufacturers and chain eateries provide estimates of the caffeine content in their coffee products.
Dunkin' Donuts is a popular coffee and donut retailer that offers a wide range of caffeinated beverages.
According to Caffeine Informer, the caffeine content of a medium cup (14 oz) of some of the coffee drinks on offer at Dunkin' Donuts is as follows:
- brewed coffee: 210 mg
- decaf brewed coffee: 10 mg
- Americano: 249 mg
- cold brew: 260 mg
- latte: 119 mg
An espresso contains 85 mg per single shot.
People can find Seattle's Best coffee products at the company's retail stores and drive-thrus as well as in some fast-food restaurants, such as Subway and Burger King.
According to Caffeine Informer, a small cup (12 oz) of some of this company's coffee products contains the following amount of caffeine:
- brewed coffee: 260 mg
- latte: 75 mg for both classic and flavored varieties
- mocha: 80 mg
A Seattle's Best espresso contains 75 mg of caffeine per single shot.
Starbucks is one of the most famous coffee brands in the world. The company list the caffeine content of their coffee products along with other nutritional information in their online drinks menu.
The caffeine content of a tall cup (12 oz) of some of Starbucks' beverages is as follows:
Several factors affect the caffeine content of a cup of coffee.
One of the main factors is the type of coffee bean. There are many different species of coffee plant, and coffee beans from different plants vary in their caffeine content.
The two most popular species of plant for producing coffee beans are:
- Coffea arabica, which people commonly refer to as Arabica
- Coffea canephora, which most people know as Robusta
According to a 2016 study, Robusta coffee beans typically contain around twice as much caffeine as Arabica beans. The researchers found that Arabica beans contain 34.1–38.5 g of caffeine per kilogram (kg) of dry coffee whereas Robusta beans contain 68.6–81.6 g of caffeine per kg of dry coffee.
Other factors that can affect the amount of caffeine in a cup of coffee include:
- the type of roast
- the brewing method
- the amount of ground coffee that a person uses during the brewing process
- the serving size
Although coffee is probably the most popular source of caffeine, many other foods and beverages also contain this chemical. However, the FDA do not require manufacturers to list the quantity of caffeine on packaged foods, beverages, or dietary supplements.
We discuss some other common sources of caffeine below:
Tea contains varying quantities of caffeine, but the amount is typically less than that of a similar-sized cup of coffee. For instance, an 8-oz cup of green tea contains around 28 mg of caffeine, while the same serving size of black tea contains around 47 mg of caffeine.
Soft drinks, such as sodas and fruit-flavored beverages, may sometimes also contain caffeine.
For example, an average 12-oz can of cola contains about 33 mg of caffeine.
Energy drinks often contain very high amounts of caffeine and sugar. This caffeine may be either synthetic or from natural sources, such as guarana leaves.
The caffeine content of energy drinks varies significantly between brands. According to the FDA, the caffeine content of these beverages typically ranges from 40 to 250 mg per 8 oz. However, some brands of energy drink can contain up to 316 mg of caffeine per 8 oz.
Chocolate naturally contains caffeine, but the amount varies according to the cacao content of the chocolate. Darker chocolate typically contains more caffeine than lighter or milk chocolate.
For example, the caffeine content of a 1-oz serving of chocolate is:
Some over-the-counter and prescription medications contain caffeine to enhance pain relief. For example, Menstrual Relief Maximum Strength is a combination of 500 mg acetaminophen, 15 mg pyrilamine maleate, and 60 mg of caffeine.
The Dietary Guidelines for Americans 2015–2020 recommend that adults consume no more than 400 mg of caffeine per day.
There are no set guidelines for children, but the American Academy of Pediatrics discourage children and adolescents from consuming caffeine, according to the FDA.
The authors of a 2017 systematic review suggest that adolescents aged 12–18 years should consume less than 100 mg of caffeine per day.
They also warn that caffeine may have a stronger effect on children under 12 years of age because they tend to weigh less. The authors conclude that young children can tolerate an average of 2.5 mg of caffeine per 1 kg of body weight.
Consuming caffeine in moderation is generally safe for most people. However, too much caffeine can cause adverse side effects.
These side effects can include:
The caffeine content of a cup of coffee can vary considerably. Factors that affect the caffeine content include the brewing method, the type of bean, and the quantity of coffee grounds that a person uses.
A typical 8-oz cup of coffee provides around 80–100 mg of caffeine, but some coffee drinks can contain significantly more.
Other sources of caffeine include energy drinks, soft drinks, chocolate, and some pain relieving medications.
The side effects of consuming too much caffeine can include headaches, sleeping difficulties, gastrointestinal issues, and jitteriness.