Coffee is one of the most common sources of caffeine. Most 8–ounce (oz) cups of coffee contain 80–100 milligrams (mg) of caffeine. However, the amount of caffeine can vary considerably depending on several factors, including the coffee type, the brewing method, and the brand.

Caffeine can be a part of a healthy diet for most people, but too much caffeine can be unsafe.

For healthy adults, approximately 400 mg per day of caffeine — about four or five cups of coffee — will typically not cause any dangerous effects.

Research shows that 85% of American adults consume caffeine daily at an average of about 180 mg per day, which equals about two cups of coffee.

This article examines the caffeine content of some different types and brands of coffee. It also covers the factors that affect the caffeine content of coffee, other sources of caffeine, the recommended daily intake of caffeine, and the side effects of caffeine.

Different types of coffee contain varying amounts of caffeine. The following list summarizes the caffeine content of some of the most common types of coffee.

Brewed coffee

An 8-oz cup of brewed coffee typically contains 80–100 mg of caffeine.

Brewed coffee involves brewing ground coffee beans in hot water. This mixture usually sits in a paper, metal, or plastic filter that separates the coffee grounds from the brewed liquid.

People can make brewed coffee in a variety of ways, such as using a filter, a percolator, or a French press.

Decaffeinated brewed

Despite its name, decaffeinated, or decaf coffee, still contains some caffeine. For instance, an average 8-oz cup of brewed decaf coffee contains about 2 mg of caffeine.

Cold brew

A 2017 study found that a 12-oz cup of cold brew coffee can contain between 153–238 mg of caffeine.

Cold brew coffee is made without heat. To make it, a person needs to steep coffee grounds in water at room temperature for 8–24 hours.

This is a different process than the way to make iced coffee, which simply involves serving brewed coffee over ice.

Instant coffee

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.

Making this type of coffee involves adding hot water to instant coffee powder or granules.

Espresso

A single 1-oz shot of espresso contains approximately 63 mg of caffeine. People make this strong coffee beverage 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.

Many manufacturers and chain eateries provide estimates of the caffeine content in their coffee products.

Dunkin’ Donuts

Dunkin’ Donuts is a popular coffee and donut retailer that offers a wide range of caffeinated beverages.

The caffeine content of a medium cup (14 oz) of some of the coffee drinks on offer at Dunkin’ Donuts is approximately as follows:

An espresso contains 118 mg per single shot.

Starbucks

Starbucks is one of the most famous coffee brands worldwide.

The company lists the caffeine content of its coffee products along with other nutritional information in its online drinks menu.

The caffeine content of a grande cup (16 oz) of some of Starbucks’ beverages is as follows:

An espresso contains 150 mg per single shot.

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 plants, 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 study’s authors found that Arabica beans contain 34.1–38.5 grams (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

For healthy adults, the Food and Drug Administration (FDA) states that typically 400 mg of caffeine should not cause dangerous or negative side effects.

The recommended amount of caffeine per day depends on the person. Different individuals can have very different sensitivities to caffeine. Certain conditions and medications may make people more sensitive to caffeine’s effects. For example:

Pregnancy and breastfeeding

The American College of Obstetricians and Gynecologists (ACOG) says that a person who is pregnant or nursing can safely consume 200 mg or one small cup of coffee daily without any negative impact on the unborn fetus or baby. However, a person may still want to consult with their doctor on the best daily dose of caffeine for them.

Children and adolescents

According to the FDA, there are no set guidelines for children, but the American Academy of Pediatrics discourages children and adolescents from consuming caffeine.

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 as 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.

Other factors impacting caffeine intake

A few other factors may cause a person to limit or avoid caffeine intake. These include:

In addition, smoking or consuming alcohol can cause the liver to metabolize caffeine much faster. This may make a person want to drink more than the recommended intake.

Though moderate consumption of caffeine should not cause any problems, people who consume more than 500 mg of caffeine daily may begin to become dehydrated. Since alcohol is also a diuretic, drinking excessive alcohol and caffeine together could cause more severe dehydration if a person does not also consume adequate fluids.

Consuming caffeine in moderation is generally safe for most people.

However, too much caffeine can cause adverse side effects.

Signs of over-consuming caffeine include:

Although coffee is probably the most popular source of caffeine, many other foods and beverages also contain the chemical.

However, the FDA does not require manufacturers to list the quantity of caffeine on packaged foods, beverages, or dietary supplements.

In addition to coffee, other common sources of caffeine are:

Tea

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 29 mg of caffeine, while the same serving size of black tea contains around 47 mg of caffeine.

Soft drinks

Soft drinks, such as sodas and fruit-flavored beverages, may also contain caffeine.

For example, an average 12-oz can of cola contains about 21 mg of caffeine.

Energy drinks

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. For example:

  • one 8.4-oz can of Red Bull energy drink contains 74.8 mg of caffeine
  • one 19-oz can of Full Throttle energy drink contains 158 mg of caffeine
  • one 8-oz can of Rockstar energy drink contains 79.2 mg of caffeine

Chocolate

Chocolate naturally contains caffeine, but the amount varies according to the cacao content of the chocolate.

Dark chocolate typically contains more caffeine than lighter or milk chocolate.

For example, the caffeine content of a 1-oz serving of chocolate is:

  • 45–59% cacao solids: 12 mg
  • 60–69% cacao solids: 24 mg
  • 70–85% cacao solids: 23 mg

Medications

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.

In addition, caffeine pills are an alternative to drinking coffee as a way to boost energy.

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 amount 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.

How much caffeine is in the average cup of coffee?

An 8-oz cup of hot brewed coffee typically contains 80–100 mg of caffeine.

Is 200 mg of caffeine a lot?

Consuming 200 mg of caffeine is the equivalent of drinking about two 8-oz cups of brewed coffee.

What is the Starbucks coffee with the most caffeine?

A Venti (20 oz) cup of Starbucks Sumatra Clover Brew coffee contains 470 mg of caffeine.

Can you overdose on caffeine?

If a person drinks too much coffee, they may experience side effects. However, a life threatening overdose from caffeine is rare. One 2018 review found 92 cases in which a person has died from a caffeine overdose.