How much caffeine is in coffee vs Earl Grey tea?

December 13, 2025 •

4 min read

An average 8-ounce cup of coffee contains roughly 95 milligrams of caffeine, while the same size cup of Earl Grey tea typically has about 40 to 70 milligrams. This difference, however, is not a simple comparison, as numerous factors can affect the final caffeine content in your mug.

Quick Summary

On average, a cup of coffee contains significantly more caffeine than a cup of Earl Grey tea, but brewing methods and steeping times heavily influence the final amount. Key factors include the type of coffee bean, tea leaf, water temperature, and preparation technique.

Key Points

Coffee has more caffeine: A standard 8-ounce cup of coffee contains approximately 95-100 mg of caffeine, significantly more than Earl Grey tea's typical 40-70 mg.
Brewing methods matter: The preparation method heavily influences caffeine extraction. For coffee, cold brew and French press often yield higher caffeine per serving than drip coffee or espresso.
Steeping time is key for tea: For Earl Grey, the longer you steep the leaves, the more caffeine is released into your cup.
L-theanine moderates tea's effect: Tea contains L-theanine, an amino acid that provides a calming effect and slows caffeine absorption, resulting in a more sustained energy boost without the jitters common with coffee.
Decaf options are available: Both coffee and Earl Grey offer decaffeinated versions for those who want to limit their caffeine intake, though trace amounts may still be present.
Robusta beans pack a punch: Coffee made from Robusta beans has nearly double the caffeine of that made from Arabica beans.

Coffee: The High-Octane Favorite

Coffee's reputation as a powerful stimulant is well-earned, with its caffeine content generally exceeding that of Earl Grey tea. While an average cup of brewed coffee contains around 95 mg of caffeine, this can fluctuate widely. The source of this stimulant is the roasted coffee bean, which has a naturally higher caffeine concentration by dry weight than tea leaves.

Factors influencing coffee's caffeine levels

Several elements contribute to the final caffeine punch in your coffee cup:

Bean Species: Robusta beans contain nearly double the caffeine of Arabica beans, giving blends with Robusta a significantly higher kick.
Brewing Method: Preparation technique is a major determinant. Espresso, while highly concentrated, is served in small volumes, meaning a standard 8-ounce drip coffee often contains more total caffeine. Cold brew, with its longer steeping time, frequently has the highest caffeine content per serving.
Grind Size: A finer grind exposes more surface area to the water, leading to quicker and more complete caffeine extraction. Conversely, a coarser grind slows the extraction process.
Roast Level: Lighter roasts often have slightly more caffeine by weight than darker roasts, as the roasting process causes beans to lose mass but not caffeine.

Earl Grey Tea: The Refined Contender

Earl Grey, a blend of black tea and bergamot oil, offers a more moderate and gentler caffeine boost compared to coffee. The caffeine is naturally present in the Camellia sinensis plant, from which black tea is made. While the bergamot flavoring adds aroma, it does not contribute to the caffeine content.

Controlling Earl Grey's caffeine content

Tea drinkers have significant control over the final caffeine level in their cup:

Steeping Time: This is the most critical factor. A longer steeping time, such as 5 minutes, will extract more caffeine from the leaves than a shorter, 1-minute steep.
Water Temperature: Hotter water extracts caffeine more efficiently. For a milder cup, using slightly cooler water can reduce the amount of caffeine released.
Leaf Size: Whole leaf teas, typical of loose-leaf varieties, release caffeine more slowly than the smaller particles or 'dust' found in many tea bags.
Decaffeination: For those who enjoy the flavor without the stimulant, decaffeinated Earl Grey versions are widely available. Herbal teas like rooibos with bergamot flavor are also an option, as they are naturally caffeine-free.

A side-by-side comparison


Feature	Coffee	Earl Grey Tea
Average Caffeine (8 oz)	95-100 mg	40-70 mg
Caffeine Peak	Often a quicker, more intense spike.	Gentler, less jittery rise due to L-theanine.
Key Factors	Bean type, brewing method, roast level.	Steeping time, water temperature, leaf size.
Decaffeinated Options	Readily available (e.g., Swiss water process).	Widely available, sometimes using herbal bases.
Energy Sensation	Strong, quick energy boost.	Milder, more sustained alertness.

Beyond caffeine: The bigger picture

The way the body processes caffeine from coffee versus tea also differs. Tea contains L-theanine, an amino acid that promotes relaxation and focus, counteracting some of the jitteriness that can accompany a strong coffee. This contributes to the milder, more sustained energy lift often associated with tea.

Furthermore, the higher antioxidant content in tea is known for various health benefits. Both beverages can be part of a healthy lifestyle when consumed in moderation. The US Food and Drug Administration suggests that healthy adults generally stay below 400 mg of caffeine per day.

Making your choice

Ultimately, the choice between coffee and Earl Grey tea depends on your personal preferences and needs. If you require a powerful, immediate energy boost, coffee is the clear winner. If you prefer a more subtle, sustained lift with less chance of jitters, Earl Grey is the better option. By understanding the factors that influence caffeine content, you can tailor your daily beverage to fit your desired energy level and experience.

Conclusion

In conclusion, an average cup of coffee delivers more caffeine than a cup of Earl Grey tea. The exact amount is highly variable for both, depending on factors like bean or leaf type, preparation method, and brewing time. Coffee offers a more pronounced and rapid stimulating effect, while Earl Grey provides a smoother, more sustained increase in alertness, partially due to the presence of L-theanine. For those seeking to manage their caffeine intake, both beverages offer pathways to control the final dosage, from brewing adjustments to choosing decaffeinated versions. The best choice is a personal one, balancing the desired energy level with potential sensitivity to caffeine.

The Difference in Caffeine Absorption

The presence of L-theanine in tea is a key differentiator in how the body experiences caffeine. This amino acid slows the body's absorption of caffeine, creating a more gentle and prolonged effect. In contrast, coffee delivers caffeine more quickly, leading to the characteristic energy rush.

For more information on the health effects and mechanisms of caffeine, visit the NCBI website.

Frequently Asked Questions

Yes, Earl Grey tea is an excellent substitute for coffee if you want a lower caffeine intake. A cup of Earl Grey has less than half the caffeine of a typical brewed coffee, providing a milder energy lift without the intensity.

Yes, brewing time is a critical factor. The longer you steep your Earl Grey, the more caffeine is extracted from the black tea leaves. A shorter steep results in a lower caffeine content.

A standard 8-ounce cup of drip coffee typically contains more total caffeine than a single 1-ounce shot of espresso. While espresso is more concentrated by volume, the larger serving size of brewed coffee gives it a higher overall caffeine amount.

The difference is due to the presence of L-theanine in tea, which is not found in coffee. L-theanine has a calming effect and slows the absorption of caffeine, leading to a more focused, sustained energy boost rather than the rapid spike and potential crash from coffee.

Yes, you can control the caffeine in your coffee by adjusting the bean type (Robusta has more caffeine than Arabica), grind size, brewing time, and roast level. Lighter roasts often have slightly more caffeine than darker ones by weight.

Yes, caffeine-free versions of Earl Grey are available. Some use decaffeinated black tea, while others use a naturally caffeine-free herbal base like rooibos infused with bergamot oil.

Most healthy adults are advised to limit their daily caffeine intake to 400 milligrams. However, pregnant women and individuals with certain health conditions should consume less.