How Much Caffeine In Coffee? What’s Its Effects On Health?

Caffeine has several health benefits. However, too much caffeine can lead to certain health problems.

Coffee is the single biggest dietary source of caffeine.

Most drink more than 1 cup (8 oz/237 ml) of coffee daily. Knowing how many mg of caffeine is in one cup of coffee is good for us to limit our daily caffeine intake to a healthy level.

On average, 95mg of caffeine is present in every cup of regular coffee. This amount can vary from 3 to 700mg in various coffee and caffeinated beverages.

Of course, the caffeine content in one cup of coffee will vary with the type and quantity of coffee powder used in it.

Let us look at some basic facts on caffeine before we examine the caffeine content in different types of coffee.

What is Caffeine?

Caffeine is a bitter substance found in coffee, tea, kola nuts, cocoa, soft drinks, chocolate, and certain medicines.

It is a xanthine alkaloid compound that acts as a stimulant in humans.

The caffeine content amount varies according to the type and serving size of food or beverage and how it’s prepared. Even the decaffeinated coffee will have some amount of caffeine in it.

Reasons For Differences In Caffeine Content In Coffee

All types of coffee do not have the same amount of caffeine present in them. Here are some of the reasons for it:

  • A lot of caffeine is lost when the coffee is roasted darker and longer; lightly roasted or green bean coffee contains more caffeine.
  • Decaf coffee, instant coffee, brewed coffee, espresso coffee, etc., significantly differ in caffeine content because of their different making process, types of beans used, and other added ingredients.
  • Robusta’ coffee beans have 50% more caffeine than Arabica beans; seventy-five percent of coffee produced worldwide is Arabica species of coffee.
  • Naturally, there is more caffeine when the quantity serving size is larger; the coffee serving cup measurements are different as it can vary from 30 to 700 ml.

How Much Caffeine In Coffee?

As we have already said, the caffeine content in coffee per cup will differ according to the type and quantity of ground coffee used.

The basic standard in the coffee industry has always been a tablespoon that is slightly mounded a little more than flat or 7 grams of coffee per 8 ounces of water. A cup of strong coffee would need 10 to 15 grams of coffee per cup.

One Shot of espresso coffee would require about 7 to 9 grams of ground coffee.

In the case of espresso coffee, the caffeine content depends on the type and size of ground coffee granules and the pressure inserted on pushing the hot water through the compressed coffee layer in the portafilter.

The caffeine in regular home-brewed coffee will vary according to the quality of the ground coffee and the speed at which the hot water is allowed to pass through the ground coffee layers in the filter.

Instant Coffee

“Instant coffee, also called soluble coffee, coffee crystals, and coffee powder, is a beverage derived from brewed coffee beans.”

It is called “instant” because you can mix one or two teaspoons of this coffee into hot water or milk and stir it for a few seconds, and your drink is ready.

Instant coffee has about 35 to 60mg of caffeine per cup, less than what is contained in regular coffee.

Regular Coffee or Brewed Coffee

The most popularly practiced method of preparing coffee drinks is brewing. The brewed coffee is also called regular coffee.

There are several different ways to brew coffee. In the US and Europe, the most commonly used method of coffee brewing is gradually pouring the boiling/hot water over the ground coffee held in a filter or by using the French press.

Brewed coffee has about 95 mg of caffeine per cup on average, and the amount can vary between 70-140 mg depending on the type of coffee bean used.

Decaf Coffee

Decaf coffee is supposed to be ‘zero’ caffeine coffee, but it is NOT.

Every type of coffee will have some amount of caffeine.

On average, one cup of decaf coffee contains 3 mg of caffeine. It may vary from 1 -7 mg per cup depending on the type of coffee beans and the decaffeination methods used.


“Espresso is coffee brewed by forcing a small amount of nearly boiling water under pressure through finely-ground coffee beans.”

Usually, the espresso coffee ground is blended from several varietals and roasts to generate a bold – not bitter, flavor.

Espresso coffee-making machines are highly precise, and it includes a set of advanced processes for making coffee.

Rightly ground coffee is tightly ramped into a “portafilter,” high-pressure hot water is forced through the ground, and liquid coffee is extracted in small and concentrated amounts.

Here are the different shots of espresso:

  • Ristretto: ¾-ounce of espresso
  • Single Shot: 1 ounce of espresso
  • Lungo: 1 ½-ounce shot of espresso
  • Double Shot: a 2-ounce shot of espresso

One Shot of espresso (usually 30ml) contains about 63 mg of caffeine.

About 125 mg of caffeine is present in double-shot espresso.

Espresso is a concentrated form of coffee. Thus, it contains more caffeine than regular coffee; each serving is very small, ¾-ounce to 2-ounce maximum, and overall caffeine intake by the user is less.

Espresso also comes in various beverage forms, such as cappuccino, macchiato, and Americano. But these varieties also contain the same amount of caffeine as in the regular espresso shots.

Caffeine In Coffee From Popular Coffee-Shop Chains

Coffee shops under the ‘big-brand’ names are common in all streets and cities in Europe and the US.

The 5 big players in the coffee shops chain are Starbucks, Dunkin Donuts, McDonald’s, Tim Hortons, and Costa Coffee; they have stiff competition from 100s of local coffee shops.

Coffee sold by large coffee brands does contain a higher amount of caffeine than home-brewed coffee.

These popular coffee shop chains have all types of brewed coffee with cup sizes ranging from 6-24 ounces (700 ml).

Starbucks Coffee

Starbucks is the No.1 world leader in coffee shops; most of the coffee items they sell have a high amount of caffeine.

The caffeine content in Starbucks’ brewed coffee is:

  • Short (80z): 180 mg
  • Tall (120z): 260 mg
  • Grande (16oz) : 330 mg
  • Venti (20oz) : 415 mg

Even decaf coffee from Starbucks contains 15–30 mg of caffeine.

McCafe Coffee

McDonald’s, under their McCafe brand, sells coffee with lower caffeine content than Starbucks.

McCafe has yet to notify or list the caffeine quantity in different coffee official treats it serves; according to private estimates, the caffeine content in their coffee servings is about 110 mg per 12 ounces.

McCafe’s decaf contains 8-14 mg, and espresso contains about 70 mg of caffeine per cup; it depends on the cup size.

Dunkin Donuts Coffee

Dunkin Donuts is another very popular Donut and coffee shop in the world. The caffeine content in the coffee they serve has about similar amount as the coffee served by Starbucks. A small cup (10 ounces) of coffee from Dunkin Donuts has 215 mg of caffeine content approximately.

  • Espresso (Single Shot):75 mg
  • Coffee Brewed (Small): 215 mg
  • Latte (Small):75 mg
  • Mocha (Small):75 mg

The decaf coffee from Dunkin unusually has a high amount of caffeine; about 53 mg of caffeine in 10 0unce decaf coffee.

Tim Hortons Coffee

Tim Hortons is Canada’s largest food service operator, even larger than McDonald’s.

Tim Hortons Coffee’s caffeine is quite high compared to home-brewed coffee.

  • Original Blend Coffee (Small): 140 mg
  • Dark Roast Coffee (Small): 135 mg
  • Decaf Coffee (Small): 6 mg
  • Café Mocha (Small): 90 mg

Costa Coffee

The largest coffee chain in the UK is Costa Coffee; it also has several outlets in about 35 countries worldwide. Originally, they were the leading roasted coffee suppliers in the world.

The caffeine quantity per 450 ml cup of Costa Coffee in popular servings is as follows:

  • Espresso (Primo Shot) :92mg
  • Flat White (Primo): 277 mg
  • Americano (Primo) :185 mg
  • Caffè Mocha (Primo) :190 mg

Caffeine Effects On Health

Caffeine helps in boosting metabolism and stimulates the nervous system. It can temporarily boost energy and make people mentally more alert.

However, too much caffeine intake may lead to mental and physical issues like variations in heart palpitations, sleep disruptions, anxiety, etc.

For a normally healthy adult, up to 400mg of caffeine intake per day may not cause any adverse effects on health. A healthy adult can consume 4 to 6 cups of brewed coffee daily.

The adverse effects of caffeine on health highly depend on the specific health conditions of each person. Some individuals are highly sensitive to even a little amount of caffeine, while others can tolerate a considerable amount of caffeine intake.

There are several health benefits of having a moderate amount of caffeine intake.

Some of the major health benefits of caffeine are:

  • Caffeine improves mental alertness and helps to boost energy levels.
  • Intake of caffeine combined with painkillers like aspirin, acetaminophen, and the ergotamine chemical is medically used to treat migraine headaches.
  • Caffeine extracts are good for relieving pain, especially when it is used in combination with painkillers.
  • Some doctors prescribe caffeine for asthma, shortness of breath in newborns, attention deficit hyperactivity disorder (ADHD), gallbladder disease, and low blood pressure.
  • Caffeine improves metabolism that, helps in weight loss and improves the sugar level in the blood to reduce the severity of Type-2 diabetes.
  • It is also a stimulant that boosts energy and improves the performance of athletes.
  • Some skin creams have caffeine as an ingredient in them as it is beneficial for reducing redness and itching in dermatitis.

Excess caffeine intake beyond the tolerance level of the individual’s health conditions could bring health woes. According to the FDA, six hundred milligrams or more per day is generally considered too much.

Side Effects Of Caffeine

Your tolerance level is affected by a person’s age, body mass, and any other health conditions. Here are some of the side effects of an overdose of caffeine intake:

  • It can affect your mood and cause physical side effects; it acts as a central nervous system stimulant.
  • If you are not used to caffeine intake, it can produce a jitter, resulting in anxiety and sleep disorder.
  • Sudden caffeine withdrawal can induce drowsiness, irritability, tremors, and anxiety.
  • Its overdose can disturb the calmness of the mind and causes confusion and hallucinations
  • It can increase acidity in the stomach, which may cause heartburn or upset the stomach.
  • It is a diuretic substance that triggers your body to get rid of water which causes dehydration.
  • Caffeine overdose can cause diarrhea, excessive thirst, and increased urination.
  • It might cause a sudden blood pressure spike, which is unhealthy for people with irregular heart rhythms.
  • A daily caffeine overdose can interfere with calcium absorption and metabolism, which may result in osteoporosis.
  • Ingesting excess caffeine is unhealthy for pregnant women as it can lead to miscarriage and affect the baby’s heartbeat.
  • In a woman, it can interfere with estrogen production and metabolism, which reduces the chances of becoming pregnant.

Final Thought

The average caffeine content of an 8-oz cup of brewed coffee is 95 mg. A single espresso or espresso-based drink contains 63 mg, and decaf coffee contains about 3 mg of caffeine (on average).

For normally healthy individuals, up to 400 mg of caffeine intake per day will not cause any harm to the body. But even a little amount of it can be bad for people sensitive to caffeine.

One cup of regular home-brewed coffee contains only 95 mg of caffeine; up to 5 cups of coffee per day won’t cause any health issues.