how much caffeine in a cup of coffee

If you are trying to reduce the amount of caffeine that you consume in a day, you may have wondered how much caffeine is there in a cup of coffee.

While an average cup of coffee contains 95 mg of caffeine, the amount may vary depending on the kind of bean used, the brewing method used and the type of coffee drink you choose.

Let us learn more about caffeine and its amount in different types of coffee.

What is caffeine?

Caffeine is a stimulant found in more than 60 plant species. These include coffee beans, tea leaves, guarana, and cocoa seeds. It stimulates the brain and the central nervous system and helps you stay alert and prevents fatigue.

Caffeine is a commonly used psychoactive drug.

According to historians, caffeine was consumed as far back as 2737 BC when Chinese Emperor Shen Nung boiled drinking water and leaves from a nearby bush, creating the first pot of tea.

Coffee was discovered in the 9th century in Ethiopia when a shepherd began consuming wild coffee berries after he observed that his goats had improved energy levels after eating them (1).

Caffeinated soft drinks were introduced in the market in the late 1800s.

How does it work?

Caffeine works by interrupting the normal adenosine pathway, which plays the vital role in regulating the feeling of ‘tiredness’ in the body and mind (2).

The size and shape of caffeine (trimethylxanthine) is similar to that of phosphodiesterase. So caffeine can block the receptors of this chemical.

If phosphodiesterase binds with a cell, it breaks down cyclic adenosine monophosphate, which leads to the release of adenosine. Caffeine blocks the effect of adenosine, leading to reduced tiredness.

Caffeine can also increase the levels of adrenaline in the blood and stimulate the activity of dopamine and norepinephrine (3).

It takes around 45 to 60 minutes for one cup of coffee to kick in after you consume it.  You can feel its effects for the next four to six hours.

Most experts do not recommend more than 400 mg of caffeine per day, which amounts to just two cups of coffee. The caffeine content in different cups of coffee can vary depending on various factors.

Factors that affect caffeine content

Several different factors have an impact on the levels of caffeine in a coffee cup. Here are the different factors that affect caffeine content in coffee:

1. Type of coffee beans

Caffeine content tends to vary according to different kinds of coffee beans and where they are grown. Robusta beans have significantly more caffeine than Arabica beans.

2. Roasting

Many people opt for dark roast coffee believing that it contains more caffeine than the lighter roast, but this is not true. When you roast the beans for a longer time, you end up losing more caffeine. A light roast of coffee contains more caffeine than dark roast.

3. Type of coffee

Caffeine content can differ for different kinds of coffee. An instant coffee cup has a much lower concentration of caffeine as compared to percolated coffee.

4. Brewing methods

The different methods used to prepare coffee include regular brewing, French press, drip coffee, and espresso. As a general rule the longer the coffee remains in the brewing process, the higher the level of caffeine it will have.

5. Serving size

Serving size also affects your caffeine consumption. One cup of coffee can range between 30 to 700 ml. Most coffee shops sell coffee in large cups that are equivalent to four standard cups.

6. Grind size

When water passes through the coffee grinds, it extracts the flavor and caffeine from it. Finer ground coffee will allow more caffeine to be extracted as it has more surface area.

Caffeine content in different types of coffee

1. Espresso

Espresso is a commonly brewed coffee across Europe. It is made by forcing a small amount of hot water, or steam, through finely ground beans. It has a bitter taste and golden hazel shine.

Espresso has more caffeine per volume than other coffees, but its servings tend to be small. A shot of espresso is just 30 to 50 ml (1 to 1.75 oz), and it contains about 63 mg of caffeine. A doppio is a double espresso, and it contains around 125 mg of caffeine (4).

2. Brewed coffee

Also known as regular coffee, brewed coffee is made by pouring boiling water on ground coffee beans. One cup (8 Oz) of this coffee contains 95 mg of caffeine (5).

Caffeine in one cup coffee infographic

3. Instant coffee

There are many varieties of ready to drink instant coffee mixes available. You can make these by adding one or two teaspoons of the coffee mix in a cup of hot water. Instant coffee contains between 30 to 90 mg of caffeine per standard cup.

4. Coffee with milk

Many coffee drinks are made from espresso and added milk. Milk helps neutralize some of the caffeine content. Some of the regular milk coffees include lattes, cappuccinos, macchiatos, and Americanos.  These coffees contain between 63 to 125 mg of caffeine.

5. Oriental coffee

Oriental coffee, also known as Turkish coffee, is made from finely ground coffee in a long-handled pot made from copper or brass. This drink contains over 135 mg of caffeine.

6. Decaf

Decaf coffee is made from coffee beans that have around 97 percent of their caffeine removed. Water, organic solvents and carbon dioxide are used to remove caffeine from these beans.

Decaf coffee is not entirely caffeine free; it contains 3 mg of caffeine per cup (6).

Caffeine levels in commercial brands

Do you know around 450,000 cups of coffee are consumed in the US every day? These include coffee brewed in homes and coffee that is sold in coffee shops.

It is generally believed that commercial coffee brands contain more caffeine than regular or home-brewed coffee.


Starbucks is amongst the most well-known coffee chains in the world. Unfortunately, it also has the most caffeinated drinks on the market.

One shot of espresso at Starbucks contains 75mg of caffeine. So most of its espresso-based drinks like Café latte (12 oz), Cappuccino (12 oz), and Caramel Macchiato (12 oz), also contain a similar amount of caffeine. Larger sizes may provide more.

Here is the caffeine content of brewed coffee at Starbucks (7):

  • Short (8 oz): 180 mg
  • Tall (12 oz): 260 mg
  • Grande (16 oz): 330 mg
  • Venti (20 oz) 415 mg

Decaf brewed coffee at Starbucks contains around 25 mg of caffeine per 16 oz.

Dunkin Donuts

Though it started as a donut bakery shop, Dunkin Donuts is famous as a coffee chain now. Dunkin Donuts reformulated their coffee in 2015 to product more caffeinated coffees, but have since then shifted back to more moderate levels.

A single shot of espresso contains 98 mg of caffeine, so most of their espresso-based drinks like a latte, cappuccino, and mocha; also contain the same amount for a 10 oz serving.

Here’s the caffeine content of brewed coffee at Dunkin Donuts (8):

  • Small (10 oz): 150 mg
  • Medium (16 oz): 210 mg
  • Large (20 oz): 300 mg
  • Extra-large (24 oz): 359 mg

A small cup of decaf coffee (brewed) contains 7 mg of caffeine, while an extra large cup (24 oz) contains 18 mg.


McCafe restaurants offer espresso-based drinks and standard brewed coffee as well. The caffeine content in their beverages can vary from store to store depending on how they prepare the beverages.

A single shot of espresso at McCafe contains 71 mg of caffeine. Some other popular drinks like Americano, latte, cappuccino, have similar caffeine content for a 12 oz serving while their decaf coffee contains 8 mg caffeine in 12 ounces.

Here’s the estimated caffeine content of brewed coffee at McDonald’s (9):

  • Small (12 oz): 109 mg
  • Medium (16 oz): 145 mg
  • Large (21 to 24 oz): 180 mg

A recent study found that the McDonald’s brewed coffee contains on average about 14.3 mg caffeine per ounce.

How much caffeine is too much?

According to the Mayo Clinic, up to 400 mg of caffeine per day is safe for most adults. So, depending on the kind of coffee you are having (brewed, espresso or instant) you can safely have between two to four cups in a day.

Though caffeine is safe for healthy adults, it should not be given to children. Pregnant and breastfeeding women should avoid or at least limit their caffeine consumption.

Certain medications like ephedrine, theophylline, and Echinacea may interact with caffeine. So people who take these medicines should avoid caffeine.

Excessive use of caffeine can cause side effects that include:

  • Migraines
  • Insomnia
  • Nervousness
  • Irritability
  • Muscle tremors
  • Fast heartbeat
  • Stomach upset
  • Frequent urination

Final thoughts

For most of us, drinking coffee is a part of our daily routine. While coffee does stimulate the brain, helps us stay alert and improve athletic performance, excessive use can be addictive and may cause side effects.

To maximize the benefits of caffeine and minimize its side effects, you should limit your daily intake.

By understanding how much caffeine is in your favorite cup of coffee, you can plan your daily consumption accordingly. So, go on and enjoy your daily cup of coffee every morning.