When choosing a coffee roast, many people assume that a darker roast means a stronger, more caffeinated brew—but is that really the case? The caffeine content in coffee is influenced by the roasting process, but not always in the way you might expect. In this article, you’ll learn how light, medium, and dark roasts compare in terms of caffeine levels, how roasting impacts the beans, and which roast might be the best choice for your morning boost.

How Much Caffeine Is in a Cup of Coffee?

You don't have to be caffeine sensitive to be curious about how much caffeine is in a cup of coffee. Maybe it's 4:30pm, but that afternoon cup sounds perfect. Maybe you're debating an after-dinner espresso. Or a second (third?) cup in the morning. 

Here’s a list of some caffeine approximations based on the USDA standard nutrition database:

• 8 fl oz coffee: 95 mg
• 8 fl oz decaf coffee: 2.4 mg
• Shot of espresso: 63 mg
• Shot of decaf espresso: 0.3 mg

For espresso capsules, our JDE capsule coffee roaster approximates the following:

• Capsule: 50-90 mg
• Decaf capsule: 2-4 mg

Caffeine content can vary depending on such factors as how and where the coffee beans were grown and how your brew is prepared, so there really aren't hard and fast rules. But there are some general guidelines to help you navigate caffeine levels and the different types of coffee roasts.

DOES LIGHT ROAST COFFEE HAVE LESS CAFFEINE THAN DARK?

Although studies have shown that dark roast coffee tends to have slightly less caffeine than lighter roasts, the difference in caffeine levels is largely due to the volume of coffee beans.

Generally, there are three roast types: light, medium, and dark. How coffee roasts are executed does matter a lot to the color, aroma, and flavor of the final product, but there’s virtually no difference in caffeine content between specific roasts.

However, the more you roast the beans, the more they dry out, making dark roast beans less dense than lighter roast beans. Consequently, a scoop of light roast beans has more actual coffee beans than a scoop of dark roast. So, if you want to consume a consistent amount of caffeine, be sure to measure your coffee by weight.

How Much Caffeine in Light Roast Coffee?

Light roast coffee contains approximately 1.13% caffeine, making it slightly lower in caffeine than medium roast but higher than dark roast. Despite the common belief that lighter roasts have more caffeine due to less roasting time, the actual difference is minimal. However, light roast coffee may retain more moisture and antioxidants compared to darker roasts.

How Much Caffeine in Medium Roast Coffee?

Medium roast coffee has a slightly higher caffeine content (1.17%) compared to light roast (1.13%) and dark roast (1.08%). The longer roasting time causes slight variations in caffeine levels, but the difference is minimal. Medium roast also has a lower acrylamide content than light roast while maintaining a balanced flavor and aroma.

How Much Caffeine in Dark Roast Coffee?

Dark roast coffee contains 1.08% caffeine, making it the lowest in caffeine compared to light and medium roasts. As roasting progresses, caffeine content decreases slightly, though not significantly enough to drastically impact energy levels. However, dark roast coffee has the highest browning index and produces the most complex volatile compounds, influencing its bold and smoky flavor.

Caffeine Levels in Coffee: What Are the Variables?

Beyond roast level, several factors influence the caffeine content of your coffee. How and when the coffee beans were grown—including altitude, climate, and soil conditions—can impact their natural caffeine levels. However, caffeine content is also affected by processing, preparation, and serving size. Below are the key variables that determine how much caffeine ends up in your cup:

• Bean Type
• Coffee Grind
• Brewing Method
• Serving Size

Bean Type

Let's quickly break down the difference between arabica beans versus robusta beans.

According to Texas A & M University: “On average, a single arabica coffee bean contains 1.9 milligrams of caffeine whereas a single robusta bean has 2.9 milligrams of caffeine.”

Arabica coffee beans dominate global trade and are typically grown at higher altitudes, offering the most refined flavors in coffee. Although named for Arabia, whence it first traded, its genetic birthplace is Western Ethiopia.

Robusta coffee beans are the second largest commercially cultivated coffee species. It’s known for its robust size (hence the name), hardiness, and caffeine content, but also for a rough taste. It has never been on the menu at Peet’s but is growing in world production.

Coffee Grind

extraction

The types of coffee grinds range from coarse to fine, with each grind size affecting caffeine extraction during brewing. Finer grinds, such as those used for espresso, expose more surface area to water, leading to faster and more efficient caffeine extraction. In contrast, coarser grinds, like those used for press pot, extract caffeine more slowly, often resulting in a milder brew.

Brewing Techniques

Different brewing methods extract caffeine at varying rates, depending on factors like water temperature, contact time, and pressure. Espresso, for example, is brewed under high pressure in a short amount of time, resulting in a concentrated shot with high caffeine per ounce. However, because serving sizes are small, the total caffeine content is lower than larger brewed coffee servings. French press (aka press pot) and cold brew, on the other hand, use a longer steeping process, allowing for more caffeine extraction, especially with a coarse grind. Drip coffee (filter coffee) falls somewhere in between, balancing extraction time and caffeine yield, making it one of the most common high-caffeine brewing methods.

Additionally, cold brew tends to have the highest caffeine concentration per serving due to its extended steeping time (often 12–24 hours). Meanwhile, Turkish coffee and Moka pot brewing produce a bold, strong coffee using a fine grind, leading to efficient caffeine extraction. Ultimately, the method you choose can significantly influence the caffeine content in your cup.

Serving Size

Serving size plays a crucial role in determining the total caffeine content in a cup of coffee. While a single shot of espresso (1 ounce) contains more caffeine per ounce than drip coffee, a standard 8-ounce cup of drip coffee typically has more total caffeine due to its larger volume. Similarly, a cold brew concentrate may be highly caffeinated, but dilution with water or milk affects the final caffeine intake. Choosing a larger serving size naturally increases caffeine consumption, making your own portion control an important factor in managing your overall intake.

Effects of Caffeine

Based on factors such as body weight, the medications you may take, and individual sensitivity, there may be such a thing as overconsuming caffeine. Watching your daily caffeine intake might mean choosing decaf beans for your first cup of the morning or switching to decaf midday.

HOW IS DECAF COFFEE MADE?

Now that we’ve established approximately how much caffeine is in a regular cup of coffee, let’s explore how much caffeine is in a cup of decaf coffee (and how it's achieved).

Peet’s does decaf a little differently than others—that’s why Peet’s decaf coffees taste as good as the real thing. We use the same high-quality beans that we use in our regular, caffeinated coffees to ensure a decaf cup with richness and depth.

All of Peet’s decaf K-Cup® pods and beans are prepped using the water process decaffeination method. Water Process is a decaffeination method that uses water instead of solvents to gently remove caffeine from raw green coffee beans. Peet's Decaffeinato Ristretto Espresso Capsules are decaffeinated using the carbon dioxide method. In the carbon dioxide decaffeination process, green coffee beans are soaked in highly compressed carbon dioxide, which extracts the caffeine, while retaining the valuable flavors of the beans. The caffeine is then removed from the beans using activated carbon filters.

To be more specific, the decaffeinator prepares a solution from pure hot water and unroasted coffee beans, then filters the caffeine out of that solution. Raw green coffee beans selected and supplied by Peet’s are soaked in the solution. Then the caffeine flows out with the solution, leaving the beans full of flavor—not caffeine. 

Peet’s uses the same beans for our decaf coffees as we do for our “full strength,” caffeinated coffees, which is how we maintain our distinctive flavor profile. Once the beans are dried, they’re ready for careful hand roasting at the Peet’s Roastery in Alameda, CA.

Because we do things a bit differently by using our own beans in our decaf coffees, at Peet’s, we feel strongly that our decaffeinated coffees are every bit as enjoyable as our regular, caffeinated coffees.

HOW MUCH CAFFEINE IN A DECAF CUP OF COFFEE?

Decaf coffees have less caffeine than their regular counterparts, but they still contain some caffeine. USDA standard nutrition database states that 1 cup (8 fl oz) brewed decaffeinated coffee has approximately 2.4 mg caffeine. We recommend you check with your doctor for guidance if you believe you may have a particular sensitivity to caffeine.

YOUR DAILY CAFFEINE INTAKE: A LOT IS UP TO YOU

As you can see, there are many factors that go into how much caffeine is in a cup of coffee. Luckily, many of these are under your control. Try a few types of Peet’s and mix and match with weighing your beans and playing with brew techniques. See if you can feel a difference. And most of all, enjoy every sip.