How Much Caffeine Is in Dark Roast Coffee?

Do you usually need a morning caffeine fix to start the day? When choosing the beans to use, how much caffeine is in dark roast coffee? Today, you're going to know the caffeine content of dark roast coffee and how certain factors may change it.

How Much Caffeine Is in Dark Roast Coffee?

On average, a 12-ounce cup of dark roasted coffee may contain 51 to 60 milligrams of caffeine. A single dark roast Arabica bean contains 1.9 milligrams of caffeine. On the other hand, a single Robusta coffee bean may have 2.9 milligrams of caffeine.

Person holding a cup of coffee

However, the bean mass, weight, coffee variety, growing conditions, and brewing method may also influence and change the caffeine content in dark roast coffee.

What Affects Caffeine Content in Dark Roast Coffee?

A regular cup of coffee may contain at least 70 milligrams of coffee. However, if you use dark roasted Kona beans, for example, this may decrease to 51 to 60 milligrams. This is mainly due to a number of chemical reasons.

Coffee Mass

Caffeine may make up 1% of a coffee bean's dry mass. Thus, if a bean weighs 100 milligrams, then the caffeine would be 1 milligram.

Due to water loss, coffee undergoing dark roasting would lose around 15% to 20% of its weight. For instance, as Kona coffee beans expand during roasting, a scoop would have fewer dark roast beans.

A spoonful of dark roasted coffee may equate to 10 beans. In contrast, the extremely dense light roasted coffee would have 12 beans despite the same size scoop. Therefore, if you are scoping based on mass, you may use fewer dark roasted coffee beans and extract less caffeine.

Weight or Volume

When you measure dark roast coffee by weight, you may need more beans to brew because a single bean weighs less than a light roast coffee bean. In some cases, this may result in a cup of dark roast coffee having more caffeine than light roast since you'll be using more beans.

Dark roast beans weigh less than light roast. During roasting, the beans also lose density and mass as the cell structure breaks down. When the bean volume increases, the caffeine in dark roast beans would decrease.Coffee beans placed around a cup of Kona coffee

Brewing Method

The way you brew coffee may impact how much caffeine you would extract. French press, drip, and coffee machine brewed coffee give dark roast coffee less caffeine.

  • French press: A 4-ounce cup of coffee extracted from a French press may contain 80 to 100 milligrams of caffeine. The constant infusion of the dark roast beans in hot water results in an aggressive extraction. This is why if you steep dark roast Kona coffee longer, the higher caffeine concentration you'll get.
  • Aeropress: An Aeropress produces about 50 to 70 milligrams of caffeine per 4-ounce of coffee. When you steep longer than the recommended 30-second brewing time, you'll get a more concentrated coffee.
  • Filter coffee: Whether pourover or drip coffee, the combination of slow extraction and hot water may produce approximately 60 to 100 milligrams of caffeine from dark roast beans.
  • Coffee machine: Suppose you want to try dark roast Kona coffee for espresso. Using a coffee machine can extract 30 to 50 milligrams of caffeine.
  • Cold brew: Dark roast cold brew typically contains around 26 milligrams of caffeine per fluid ounce. Caffeine is highly soluble in water. The hotter the water, the more caffeine you extract, which is why cold water can better control the caffeine content.

Coffee Variety

Robusta contains almost twice the caffeine content than Arabica. This is why it has a harsh-tasting taste to Arabica coffee beans. On average, a single Robusta coffee bean produces 2.9 milligrams of caffeine. On the other hand, a single dark roast Arabica bean may only have 1.9 milligrams of caffeine.

Growing Conditions

Caffeine is a natural stimulant that coffee plants produce to serve as a natural pesticide. This is why Robusta beans can withstand environmental stresses in regions with low altitudes. 

On the other hand, coffee beans grown in high altitudes have less caffeine. Likewise, even dark roasted Lava Lei Kona beans that grow in the high slopes of the Kona Big Belt have less caffeine. 

Person pouring coffee for her friend

Grind Size

Finer coffee grounds provide more surface area than coarse grind, letting you extract more caffeine. Since dark roasted coffee is less dense, you may need a slightly coarser grind to extract the most flavor and caffeine.

What Are the Benefits of Caffeine in Dark Roast Coffee?

It's relatively safe to consume 400 to 600 milligrams of caffeine daily. This may equate to 4 to 6 eight-ounce cups of dark roasted coffee. Even if you drink two 12-ounce cups of dark roasted coffee, you would still be well below the recommended limit and get these benefits.

  • Increase fat-burning abilities: Drinking dark roasted Kona coffee may increase metabolism by 11%. This means consuming 300 milligrams of caffeine lets you burn extra 79 calories per day.
  • Boost energy level: Caffeine can serve as a stimulant for the central nervous system. It can increase neurotransmitter levels in the brain that regulate energy levels, including dopamine. This is why caffeine is a great way to fight fatigue.
  • Improve brain health: Study shows that drinking coffee enhances concentration and improves mental alertness due to caffeine. Caffeine increases serotonin and acetylcholine. These compounds can stimulate the brain to stabilize the blood-brain barrier and improve memory.
  • Improve liver health: Caffeine metabolizes to paraxanthine, which helps slow the growth of scar tissues in the liver.
  • Anti-aging and skin brightening properties: Caffeine is an antioxidant that can protect the skin from damage. It stops free radicals from breaking down the body's collagen, resulting in fine lines, wrinkles, and saggy skin.


A 12-ounce cup of dark roasted coffee may contain up to 60 milligrams of caffeine, whereas a dark roast Arabica bean has about 1.9 milligrams. With the dark roast beans from Lava Lei 100% Kona coffee, you can get caffeine's invigorating punch while savoring the sweet and fruity flavor of Kona.